Disable hover on errorbars plot

[maximlt]

Fixes issues seen when recently building the dev docs. I don't know why this raised an error while it used to run fine, Bokeh has become more strict in some way?

[maximlt]

@jlstevens could you please review this PR? We need a fix for this issue (described more in details below) that is currently breaking the build of a few pages of the site (this one for example: https://pyviz-dev.github.io/hvplot/reference/pandas/errorbars.html#pandas-gallery-errorbars).

Two runs failed, one on macos & python 3.7 that is expected since there's currently an issue with fiona/pyproj on conda-forge (I'm tracking that), and one on Windows & Python 3.7 that just timed out but ran fine after a previous commit (https://github.com/holoviz/hvplot/runs/5696022365?check_suite_focus=true).

Basically it seems that no error bars plot can be rendered with hvplot. A simple example to reproduce is:

import hvplot.pandas  # noqa
from bokeh.sampledata import perceptions

data = perceptions.numberly.describe().transpose().sort_values('mean')
data.hvplot.scatter(y='mean', ylabel='amount') * data.hvplot.errorbars(y='mean', yerr1='std')

which generates this traceback:

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/IPython/core/formatters.py:973, in MimeBundleFormatter.__call__(self, obj, include, exclude)
    970     method = get_real_method(obj, self.print_method)
    972     if method is not None:
--> 973         return method(include=include, exclude=exclude)
    974     return None
    975 else:

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/core/dimension.py:1316, in Dimensioned._repr_mimebundle_(self, include, exclude)
   1309 def _repr_mimebundle_(self, include=None, exclude=None):
   1310     """
   1311     Resolves the class hierarchy for the class rendering the
   1312     object using any display hooks registered on Store.display
   1313     hooks.  The output of all registered display_hooks is then
   1314     combined and returned.
   1315     """
-> 1316     return Store.render(self)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/core/options.py:1405, in Store.render(cls, obj)
   1403 data, metadata = {}, {}
   1404 for hook in hooks:
-> 1405     ret = hook(obj)
   1406     if ret is None:
   1407         continue

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/ipython/display_hooks.py:282, in pprint_display(obj)
    280 if not ip.display_formatter.formatters['text/plain'].pprint:
    281     return None
--> 282 return display(obj, raw_output=True)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/ipython/display_hooks.py:252, in display(obj, raw_output, **kwargs)
    250 elif isinstance(obj, (CompositeOverlay, ViewableElement)):
    251     with option_state(obj):
--> 252         output = element_display(obj)
    253 elif isinstance(obj, (Layout, NdLayout, AdjointLayout)):
    254     with option_state(obj):

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/ipython/display_hooks.py:146, in display_hook.<locals>.wrapped(element)
    144 try:
    145     max_frames = OutputSettings.options['max_frames']
--> 146     mimebundle = fn(element, max_frames=max_frames)
    147     if mimebundle is None:
    148         return {}, {}

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/ipython/display_hooks.py:192, in element_display(element, max_frames)
    189 if type(element) not in Store.registry[backend]:
    190     return None
--> 192 return render(element)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/ipython/display_hooks.py:68, in render(obj, **kwargs)
     65 if renderer.fig == 'pdf':
     66     renderer = renderer.instance(fig='png')
---> 68 return renderer.components(obj, **kwargs)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/plotting/renderer.py:410, in Renderer.components(self, obj, fmt, comm, **kwargs)
    408 doc = Document()
    409 with config.set(embed=embed):
--> 410     model = plot.layout._render_model(doc, comm)
    411 if embed:
    412     return render_model(model, comm)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/panel/viewable.py:460, in Renderable._render_model(self, doc, comm)
    458 if comm is None:
    459     comm = state._comm_manager.get_server_comm()
--> 460 model = self.get_root(doc, comm)
    462 if config.embed:
    463     embed_state(self, model, doc,
    464                 json=config.embed_json,
    465                 json_prefix=config.embed_json_prefix,
    466                 save_path=config.embed_save_path,
    467                 load_path=config.embed_load_path,
    468                 progress=False)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/panel/viewable.py:518, in Renderable.get_root(self, doc, comm, preprocess)
    501 """
    502 Returns the root model and applies pre-processing hooks
    503 
   (...)
    515 Returns the bokeh model corresponding to this panel object
    516 """
    517 doc = init_doc(doc)
--> 518 root = self._get_model(doc, comm=comm)
    519 if preprocess:
    520     self._preprocess(root)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/panel/layout/base.py:122, in Panel._get_model(self, doc, root, parent, comm)
    120 if root is None:
    121     root = model
--> 122 objects = self._get_objects(model, [], doc, root, comm)
    123 props = dict(self._init_params(), objects=objects)
    124 model.update(**self._process_param_change(props))

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/panel/layout/base.py:112, in Panel._get_objects(self, model, old_objects, doc, root, comm)
    110 else:
    111     try:
--> 112         child = pane._get_model(doc, root, model, comm)
    113     except RerenderError:
    114         return self._get_objects(model, current_objects[:i], doc, root, comm)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/panel/pane/holoviews.py:239, in HoloViews._get_model(self, doc, root, parent, comm)
    237     plot = self.object
    238 else:
--> 239     plot = self._render(doc, comm, root)
    241 plot.pane = self
    242 backend = plot.renderer.backend

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/panel/pane/holoviews.py:312, in HoloViews._render(self, doc, comm, root)
    309     if comm:
    310         kwargs['comm'] = comm
--> 312 return renderer.get_plot(self.object, **kwargs)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/plotting/bokeh/renderer.py:73, in BokehRenderer.get_plot(self_or_cls, obj, doc, renderer, **kwargs)
     66 @bothmethod
     67 def get_plot(self_or_cls, obj, doc=None, renderer=None, **kwargs):
     68     """
     69     Given a HoloViews Viewable return a corresponding plot instance.
     70     Allows supplying a document attach the plot to, useful when
     71     combining the bokeh model with another plot.
     72     """
---> 73     plot = super(BokehRenderer, self_or_cls).get_plot(obj, doc, renderer, **kwargs)
     74     if plot.document is None:
     75         plot.document = Document() if self_or_cls.notebook_context else curdoc()

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/plotting/renderer.py:243, in Renderer.get_plot(self_or_cls, obj, doc, renderer, comm, **kwargs)
    240     defaults = [kd.default for kd in plot.dimensions]
    241     init_key = tuple(v if d is None else d for v, d in
    242                      zip(plot.keys[0], defaults))
--> 243     plot.update(init_key)
    244 else:
    245     plot = obj

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/plotting/plot.py:991, in DimensionedPlot.update(self, key)
    989 def update(self, key):
    990     if len(self) == 1 and ((key == 0) or (key == self.keys[0])) and not self.drawn:
--> 991         return self.initialize_plot()
    992     item = self.__getitem__(key)
    993     self.traverse(lambda x: setattr(x, '_updated', True))

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/plotting/bokeh/element.py:2361, in OverlayPlot.initialize_plot(self, ranges, plot, plots)
   2359 if self.tabs:
   2360     subplot.overlaid = False
-> 2361 child = subplot.initialize_plot(ranges, plot, plots)
   2362 if isinstance(element, CompositeOverlay):
   2363     # Ensure that all subplots are in the same state
   2364     frame = element.get(key, None)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/plotting/bokeh/element.py:1418, in ElementPlot.initialize_plot(self, ranges, plot, plots, source)
   1415     self.handles['y_range'] = plot.y_range
   1416 self.handles['plot'] = plot
-> 1418 self._init_glyphs(plot, element, ranges, source)
   1419 if not self.overlaid:
   1420     self._update_plot(key, plot, style_element)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/plotting/bokeh/element.py:1384, in ElementPlot._init_glyphs(self, plot, element, ranges, source)
   1381 if isinstance(renderer, Renderer):
   1382     self.handles['glyph_renderer'] = renderer
-> 1384 self._postprocess_hover(renderer, source)
   1386 # Update plot, source and glyph
   1387 with abbreviated_exception():

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/holoviews/plotting/bokeh/element.py:1351, in ElementPlot._postprocess_hover(self, renderer, source)
   1349     hover.renderers = []
   1350 if renderer not in hover.renderers:
-> 1351     hover.renderers.append(renderer)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/bokeh/core/property/wrappers.py:140, in notify_owner.<locals>.wrapper(self, *args, **kwargs)
    138 old = self._saved_copy()
    139 result = func(self, *args, **kwargs)
--> 140 self._notify_owners(old)
    141 return result

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/bokeh/core/property/wrappers.py:169, in PropertyValueContainer._notify_owners(self, old, hint)
    167 def _notify_owners(self, old: Unknown, hint: DocumentPatchedEvent | None = None) -> None:
    168     for (owner, descriptor) in self._owners:
--> 169         descriptor._notify_mutated(owner, old, hint=hint)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/bokeh/core/property/descriptors.py:594, in PropertyDescriptor._notify_mutated(self, obj, old, hint)
    590 value = self.__get__(obj, obj.__class__)
    592 # re-validate because the contents of 'old' have changed,
    593 # in some cases this could give us a new object for the value
--> 594 value = self.property.prepare_value(obj, self.name, value, hint=hint)
    596 self._set(obj, old, value, hint=hint)

File /usr/share/miniconda/envs/test-environment/lib/python3.8/site-packages/bokeh/core/property/bases.py:365, in Property.prepare_value(self, owner, name, value, hint)
    363 else:
    364     obj_repr = owner if isinstance(owner, HasProps) else owner.__name__
--> 365     raise ValueError(f"failed to validate {obj_repr}.{name}: {error}")
    367 if isinstance(owner, HasProps):
    368     obj = owner

ValueError: failed to validate HoverTool(id='1007', ...).renderers: expected an element of either Auto or List(Instance(DataRenderer)), got [None]