switch to ruff for formatting / linting

[hartytp]

It's much better than flake8 / black.

I've just done this for the atomic physics package so this is just a matter of copy-paste.

[dnadlinger]

Sounds good to me – looks like deciding on a good set of lints might require some work going through the list of available ones, though.

[hartytp]

The defaults for ruff are pretty comparable to flake8 and I'm happy with it as an approximately like for like switch without configuration (e.g. even just the --fix option is a really nice quality of life improvement).

I agree though that there are is a lot of additional static analysis which isn't enabled by default and it's worth someone spending a little time seeing what else it makes sense to enable.