Bug 1845516 - Enable math-style and math-depth by default. r=emilio

After bug 1667090 and bug 1665975, the work is done so we can enable
these two related flags.

I2S: https://groups.google.com/a/mozilla.org/g/dev-platform/c/Uk39hvO910w/m/rBwWIfmLCAAJ

Differential Revision: https://phabricator.services.mozilla.com/D184576

Author: fred-wang

modules/libpref/init/StaticPrefList.yaml

@@ -8608,14 +8608,14 @@
 # Is support for math-style enabled?
 - name: layout.css.math-style.enabled
   type: RelaxedAtomicBool
-  value: @IS_NIGHTLY_BUILD@
+  value: true
   mirror: always
   rust: true
 
 # Is support for math-depth enabled?
 - name: layout.css.math-depth.enabled
   type: RelaxedAtomicBool
-  value: @IS_NIGHTLY_BUILD@
+  value: true
   mirror: always
   rust: true
 

testing/web-platform/meta/css/css-fonts/math-script-level-and-math-style/__dir__.ini

@@ -1,2 +1 @@
-prefs: [layout.css.math-style.enabled: true, layout.css.math-depth.enabled: true]
 leak-threshold: [utility:51200]

testing/web-platform/meta/mathml/__dir__.ini

@@ -1 +1 @@
-prefs: [mathml.mathspace_names.disabled: true, layout.css.math-depth.enabled: true, layout.css.math-style.enabled: true, mathml.legacy_mathvariant_attribute.disabled: true]
+prefs: [mathml.mathspace_names.disabled: true, mathml.legacy_mathvariant_attribute.disabled: true]