Checkers rst

[khancyr]

move check-ref-directives from update.py to pre-commit (gain 6s on build)
add another check on :ref: directives.
Add unittitest for both rst checks
make both rst check use pre-commit venv to run and not system one's.

tested locally with pre-commit run --all-files (all passed) and CI validate this also

[Hwurzburg]

does this mean those checks do not occur on local builds? I think that this means one would HAVE to run not only update.py but pre-commit to check local builds thoroughly before pushing as a PR to master, correct? would impact my workflow, but probably mainly only me

[khancyr]

pre-commit should be part of the workflow anyway now, as we require it to pass CI. That is why I moved the check from update.py to pre-commit.
Another advantage is that is speed up a bit update.py so we need only one run with pre-commit to catch all the syntax mistakes

[Hwurzburg]

@peterbarker ping

[peterbarker]

Does this mean you can make lots of changes and only discover there's a problem when you go to commit, rather than when you run update.py?

[khancyr]

That is already the case, we have only one syntax check on update.py and it is not blocking, all other checks are on pre-commit call.
Notice that those check aren't failing sphinx build that why we added them.

If you prefer the other way, we could call pre-commit checks from update.py, that would and make it blocking. That would force the check to run without being too slow

[Hwurzburg]

and there is a difference between server builds and local developer builds....AFAIAC, having update.py warnings for errors on local builds (no blocking to the site build locally) is fine....