Fix quantum volume notebooks

[mpharrigan]

fixes #3501

[balopat]

Thanks for the fix!!! Can you remove the skip line from dev_tools/notebook_tests.py as well?
Here

Cirq/dev_tools/notebook_test.py

Lines 30 to 32 in 905083c

	# skipping quantum volume notebooks as they have issues
	# see https://github.com/quantumlib/Cirq/issues/3501
	"examples/advanced/*.ipynb",

[mpharrigan]

Done; I don't understand the test failure

[mpharrigan]

Now it's a different error.

1. The notebook test failures are impossible to read. The bash color codes don't get rendered right and the rest of it is in JSON / html
2. Why can't it import cirq? Presumably we install that before running the notebook and/or the notebook has a pip install cell

[balopat]

Now it's a different error.

1. The notebook test failures are impossible to read. The bash color codes don't get rendered right and the rest of it is in JSON / html

Yes, agreed, to be improved. I think we should be able to output this json into a notebook that then could be previewed within github actions, or be downloadable, or even better if we can make the error more readable and colored within the log. Opened #3620.

2. Why can't it import cirq? Presumably we install that before running the notebook and/or the notebook has a pip install cell

This is exactly the kind of error the devsite pipelines caught before and were not an issue if you ran a notebook in a virtualenv with cirq installed. On the path for cirq installation (which is taken here), you'll need to run an import cirq before the first usage of it. Which in this case it seems like from the logs (which I agree is hard to find) is this line:

"qubits = cirq.GridQubit.rect(3,2)\n",