Type hints in residuals.py & bump black to 24.x

[abhisrkckl]

No description provided.

[dlakaplan]

Do we need to bump black now? I thought the annual updates happened in Jan, so maybe we are just very late?

[abhisrkckl]

We were using black 23 in tox.ini and black 24 in the pre-commit file. It was working till now for some reason.
But black 24.8 dropped last week, breaking the black CI test for this PR. Bumping the black version was the only way to make it work.

I think we should be bumping the black version anyway, and this is as good a time as any, in my opinion.

[abhisrkckl]

#1709

[dlakaplan]

OK, that makes sense.

[dlakaplan]

I can merge this when you are set.

[abhisrkckl]

This is ready to go.