Use ruff instead of flake8 + isort

[Kludex]

It looks like everybody is using it: https://ruff.pages.dev/

Should we use it as well on encode projects? cc @tomchristie @florimondmanca @adriangb

[adriangb]

I would be open to it, yes

[florimondmanca]

Oh, looking neat. Is the speedup that significant and worthwhile? I’ll try on a couple of libraries of mine. If this doesn’t cause too much breakage I’d also be open to it.

[Kludex]

I've created #2648 cc @tomchristie