Format with ruff instead of black

[morbult]

This PR replaces black with ruff's formatter. Ruff is already used for linting so why not use one tool instead of two here.

Line length is kept at 120.

As seen in ee60e89, some things are formatted a little differently although ruff is designed as a drop-in replacement for black.
Some deviations are known and I think in this case these are all the deviations happening:

• https://docs.astral.sh/ruff/formatter/black/#blank-lines-at-the-start-of-a-block
• https://docs.astral.sh/ruff/formatter/black/#f-strings
• https://docs.astral.sh/ruff/formatter/black/#implicit-concatenated-strings
• https://docs.astral.sh/ruff/formatter/black/#call-chain-calls-break-differently-in-some-cases

[zariiii9003]

Maybe this could be replaced with pre-commit autoupdate && pre-commit run -a if Daniel is okay with it. Then there's no need to specify ruff versions in multiple places.

[morbult]

Thanks for reviewing. I haven't used pre-commit but if I understand correctly this change would require each contributor to first install pre-commit and install it on this repo, otherwise they would just get an error. So should we also add pip install -U pre-commit && pre-commit install before?