Update sphinx

[A5rocks]

I was looking at #2921 and wondering why Sphinx wasn't getting updated. Turns out they dropped support for Python 3.8. However, our RTD build runs in Python 3.11 so we can use that for the docs requirements.

[A5rocks]

/home/docs/checkouts/readthedocs.org/user_builds/trio/checkouts/3070/src/trio/abc.py:docstring of trio.abc.Channel:1: WARNING: py:class reference target not found: trio._abc.SendChannel
/home/docs/checkouts/readthedocs.org/user_builds/trio/checkouts/3070/src/trio/abc.py:docstring of trio.abc.Channel:1: WARNING: py:class reference target not found: trio._abc.ReceiveChannel
/home/docs/checkouts/readthedocs.org/user_builds/trio/checkouts/3070/src/trio/__init__.py:docstring of trio.SocketListener:1: WARNING: py:class reference target not found: trio._abc.Listener
/home/docs/checkouts/readthedocs.org/user_builds/trio/checkouts/3070/src/trio/__init__.py:docstring of trio.SSLListener:1: WARNING: py:class reference target not found: trio._abc.Listener
/home/docs/checkouts/readthedocs.org/user_builds/trio/checkouts/3070/src/trio/__init__.py:docstring of trio.SSLListener:1: WARNING: py:class reference target not found: trio._ssl.SSLStream
/home/docs/checkouts/readthedocs.org/user_builds/trio/checkouts/3070/src/trio/__init__.py:docstring of trio.DTLSChannel:1: WARNING: py:class reference target not found: trio._abc.Channel
/home/docs/checkouts/readthedocs.org/user_builds/trio/checkouts/3070/src/trio/lowlevel.py:docstring of trio.lowlevel.Task.iter_await_frames:1: WARNING: py:class reference target not found: types.FrameType

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.63%. Comparing base (6f614ec) to head (3cfd9b3).
Report is 239 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3070   +/-   ##
=======================================
  Coverage   99.63%   99.63%           
=======================================
  Files         121      121           
  Lines       17850    17855    +5     
  Branches     3208     3208           
=======================================
+ Hits        17784    17789    +5     
  Misses         46       46           
  Partials       20       20           

Files with missing lines	Coverage Δ
src/trio/_abc.py	100.00% <100.00%> (ø)
src/trio/_ssl.py	100.00% <100.00%> (ø)

---- 🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests

[A5rocks]

Ok most of those is that Sphinx doesn't seem to like referencing a superclass. That makes no sense!

Somehow the changes are from sphinx-doc/sphinx@1ff9adf. Because it's trying to refer to the classes it derives from and then tries getting them from _abc.... I hate updating Sphinx.

[A5rocks]

OK filed python/cpython#123250, but there's things we can do to work around this.

[CoolCat467]

Looks good. python/cpython#123250 is quite interesting, I hope there will be a fix eventually. I was wondering while looking at this, any particular reason to use 3.11 over 3.12 now that we are upgrading?

[A5rocks]

No, just when we changed the version I think it wasn't supported by RTD.

[jakkdl]

sad to need ugly workarounds, but seems worth it