Use ruff for formatting

[rnestler]

This is just a quick PR to answer the following questions:

• Should we add a code format check to CI? Yes. Done.
• Is the configuration like this OK? Yes. Done.
• Should we reformat the whole repo? Yes. Done.
• Should we also replace flake8 with ruff? Yes. Done.

[ubruhin]

I have no clear opinion about this. Generally I like consistent and enforced formatting and also the style looks quite good to me. But especially some configuration lists (e.g. FetConfig or ChipConfig) are getting more verbose / harder to read. Though not too bad I guess 🤔 Anyway, I would prefer a shorter line length.

Btw I never hear of ruff, so no opinions about that tool 😉

[dbrgn]

I'm a fan of autoformatters, as long as they allow sufficient control and can be disabled for certain parts of the code if necessary. So +1 from my side for ruff.

[z3ugma]

Are you encouraging users to switch to uv as well? Using [project.optional-dependencies] and having a [test] group installed with pip is a little awkward compared to using dev dependencies https://docs.astral.sh/uv/concepts/projects/dependencies/#dependency-groups

for example:

librepcb_parts_generator % uv sync --group test
Resolved 25 packages in 50ms
error: Group `test` is not defined in the project's `dependency-groups` table

as opposed to moving to this in pyproject.toml:

[dependency-groups]
dev = ["pytest", "mypy == 1.10.0", "ruff ~= 0.12.2"]

librepcb_parts_generator % uv sync --group dev 
Resolved 25 packages in 49ms
Prepared 3 packages in 1.69s
Installed 3 packages in 17ms
 + mypy==1.10.0
 + mypy-extensions==1.1.0
 + ruff==0.12.4

[ubruhin]

Are you encouraging users to switch to uv as well?

I'd suggest to do so, and adjust pyproject.toml & README.md accordingly, but I'd prefer getting this PR merged first, and then do the other updates. It would be nice if this PR was merged as soon as possible to not create conflicts with other updates.

@rnestler Do you intend to add some fmt: off/on markers to fix the verbose formatting of config blocks? Or do you want me to do it?

[z3ugma]

@rnestler have you got time to push this forward? I rebased ahead of these changes for #145

[z3ugma]

@rnestler can you progress this Ruff formatting PR so that I can merge my changes that are behind it? Or let me know if you're busy and want to me take this over

[ubruhin]

Or let me know if I should take it over @rnestler
I think only some #fmt: off/on need to be added before running the formatter.

EDIT: Ah I didn't see @z3ugma also offered to take it over 🙈

[rnestler]

Sorry for radio silence 🙈 I was on holidays the last two weeks.

[rnestler]

@z3ugma If you have time and capacity you can take over, thanks for the offer 🙂

[ubruhin]

Due to the silence again, I have now applied all the #fmt: off/on by myself and will merge it soon.