Update setup-python action version

[brandonwillard]

This PR updates the setup-python action in our workflows, which should remove a few of the deprecation warnings.

It looks like there are some Python version issues in the docs build process, so this PR includes some commits that address those issues.

[maresb]

Yes, as long as everything passes this looks very good to me. I would have done this in the other PR except I wanted to keep the changes focused and minimal (easier one thing at a time). And I can rebase #1375. Thanks!

[maresb]

Along these lines, how much longer do you plan to support Python 3.7? Support in other libraries is beginning to be phased out. It would be nice to be able to bump requires-python to 3.8.

[brandonwillard]

I added a few more minor fixes that should help the Sphinx documentation generation process.

[brandonwillard]

Along these lines, how much longer do you plan to support Python 3.7? Support in other libraries is beginning to be phased out. It would be nice to be able to bump requires-python to 3.8.

I'm fine with that change. We might want to bundle it with the next big release, though.

[maresb]

Just saw that a test for #4324 failed with a nonsensical error from setup-python, so hopefully this will help.

https://github.com/aesara-devs/aesara/actions/runs/3796153938/jobs/6455995636

[codecov]

Codecov Report

Merging #1376 (4108323) into main (f874925) will increase coverage by 0.00%.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1376   +/-   ##
=======================================
  Coverage   74.68%   74.69%           
=======================================
  Files         195      195           
  Lines       49744    49748    +4     
  Branches    10529    10529           
=======================================
+ Hits        37153    37157    +4     
  Misses      10266    10266           
  Partials     2325     2325           

Impacted Files	Coverage Δ
aesara/tensor/math.py	90.39% <100.00%> (-0.02%)	⬇️
aesara/tensor/var.py	87.82% <100.00%> (+0.13%)	⬆️

[maresb]

Looks ready to merge

[maresb]

Perhaps we should configure one/some of those actions which automatically opens PRs to update these things.

[brandonwillard]

Perhaps we should configure one/some of those actions which automatically opens PRs to update these things.

That would be cool!