Fix problem with monospace rendering in Vivaldi

[ZedThree]

Fixes #98

[cpython-cla-bot]

All commit authors signed the Contributor License Agreement.

[ezio-melotti]

What browsers have you tested this with?
Do we know why the quoted `"monospace" was included and should we keep it somewhere in the list?

[hugovk]

Quoted "monospace" was added in #85 to workaround a Chrome bug, which was fixed in Chrome 96 (Nov 2021): python/pythondotorg#1708 (comment).

By now, there's very little usage of Chrome 96 and older versions. Chrome 96% is 0.04% at https://caniuse.com/usage-table, and it's something like 1.68% for 96 and older.

(It would be good if we could hook up PR previews on Read the Docs or Netlify, that would make testing easier.)

[ZedThree]

I tested with Vivaldi 5.6.2867.62 and Firefox 109.0

[hugovk]

Tested building CPython docs locally using:

diff --git a/Doc/requirements.txt b/Doc/requirements.txt
index 134f39d6d7..c6d9c6a663 100644
--- a/Doc/requirements.txt
+++ b/Doc/requirements.txt
@@ -12,4 +12,4 @@ sphinxext-opengraph>=0.7.1
 
 # The theme used by the documentation is stored separately, so we need
 # to install that as well.
-python-docs-theme>=2022.1
+git+https://github.com/ZedThree/python-docs-theme@fix-monospace-vivaldi#egg=python-docs-theme

Looks fine on macOS Ventura 13.1 and Chrome 108:

And Safari 16.2:

And Firefox 109:

And Opera 93:

[hugovk]

And I've put a preview build up at https://hugovk-cpython.readthedocs.io/en/python-docs-theme-pr-104/ if anyone else wants to test it.

Looks fine with Chrome 109 on Samsung S10 with Android 12.

[hugovk]

Thank you!