MNT: upgrade ruff pre-commit hook, move its configuration out of pre-commit-config.yaml and fix lints

[neutrinoceros]

Moving ruff's config to ruff.toml allows running ruff's LSP in an IDE and see lints before git commit is invoked.
I also upgraded the tool to a much more recent version and applied newly discovered lints.

[neutrinoceros]

Seeing a couple failures with

TypeError: zip() takes no keyword arguments

which indicate that the python interpreter used in CI is older than 3.10.
While I strongly recommend upgrading it at least to 3.11¹, I could also adjust settings to preserve compatibility with an older Python version, though in this case, please let me know how far back you'd like me to go.

Footnotes

1. for motivation Python 3.9 is EOL already and 3.10 will be too in about 6 month ↩

[neutrinoceros]

updated base branch to develop

[glesur]

python updated to 3.14 from sources on the self-hosted runner. Should work fine.

[neutrinoceros]

thanks. Pre-commit still failed on CI but it looks like some unrelated networking error.

[neutrinoceros]

linting passed, but now the env under which tests are run looks broken.

[glesur]

tests are failing because somehow #367 is not included upstream. Can you rebase ?

[neutrinoceros]

I don't think that's it. I did check that commits from #367 are in my branch's history. In any case rebasing locally turned into a no-op