DM-54006: Update docs action to sphinxutils and require Python 2.12

[MichelleGower]

Checklist

• ran Jenkins
• added a release note for user-visible changes to doc/changes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.31%. Comparing base (7f70f0d) to head (a537207).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #228   +/-   ##
=======================================
  Coverage   90.31%   90.31%           
=======================================
  Files          51       51           
  Lines        5545     5545           
  Branches      540      540           
=======================================
  Hits         5008     5008           
  Misses        438      438           
  Partials       99       99           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[MichelleGower]

I first missed updating the action that runs 3.11. I forced push the change (probably while tests were still running). Now it seems like there's a hung 3.11 test. Can't click on the 3.11 test. Yesterday could click on hung tests and would see a couple lines and then waiting for a runner, so this is something different. Rerunning tests doesn't fix it. Pushing just reruns the 3.12 and greater tests as expected but doesn't remove the 3.11 test. Going to close this PR and open a new one to try to get a clean set of tests.