Update to sphinx 7

[GrahamSH-LLK]

Currently first pass

[sciencewhiz]

Unfortunately, It's fairly common for things to break on big upgrades like this in the past.

Here's what I've noticed:

• colors on the front page panels shifted slightly (not necessarily a problem, but a possible indication of other CSS issues)
• 404 page is all messed up
• sphinx-rtd-theme v2 (which looks to add support for Sphinx 7) should be released soon. Not sure what might be broken with the older version. Looks like 1.3 is ok for Sphinx 7

I'm not sure if there's a way to see if translations or pdf/html still works without merging @Daltz333

[Daltz333]

You can build translations locally to test, but I'd just rely on CI to test PDF builds.

[sciencewhiz]

Looks like translations failed
CI PDF looks reasonable
build times look to be about the same

[GrahamSH-LLK]

wpilibsuite/frc-docs-translations#36 should fix the translations
404 also works now

[sciencewhiz]

The colors on the front panels seem back to normal

[Daltz333]

Needs a rebase

[GrahamSH-LLK]

Needs a rebase

Rebased and builds succeeding.

[GrahamSH-LLK]

@sciencewhiz Strange that it failed. I can repro the problem locally by running the command that rtd runs for whatever part of the build it is that failed. However, I can't figure out where the problem is as the stack trace is fairly unhelpful.

[sciencewhiz]

@TheTripleV identified the problem as being from https://github.com/wpilibsuite/frc-docs/blob/main/source/_extensions/rtd_patch.py

[TheTripleV]

Adding *args, **kwargs to both inits (definition and call) should make it work on current sphinx and sphinx 7.

[GrahamSH-LLK]

Fixed PR in #2395