(🎁) add ruff config

[KotlinIsland]

Ruff covers flake8's ruleset, but also the ruleset of 20 or so other linters, plus it's much much faster, also it can automatically fix a lot of issues. We can remove a bunch of these configs if you think it's too many rules to enforce. We can just stick to the flake8 ones maybe.

https://github.com/astral-sh/ruff
https://docs.astral.sh/ruff/rules

[KotlinIsland]

@ymyzk Is there any reason to not merge this? not having a lint CI run on pull requests is a little painful

[ymyzk]

Ah, sorry. I left code review comments, but forgot to click the submit button. Let me do so now.

[ymyzk]

I prefer not to maintain a long list of configuration for this project. I've been using flake8 as it's simple and sufficient for this project.

[KotlinIsland]

ruff covers flake8's ruleset, but also the ruleset of 20 or so other linters, plus it's much much faster, also it can automatically fix a lot of issues. We can remove a bunch of these configs if you think it's too many rules to enforce. We can just stick to the flake8 ones maybe.

[KotlinIsland]

But I think that isort and pyupgrade are really good ones to keep.

[ymyzk]

Thanks for elaborating the context. I understand you prefer to use ruff with many rules and I understand people have different preferences on CI tooling.

However, I don't see a need to use so many lint tools for this project considering that the code base is relatively small and simple. Also, we don't have a need to use a faster lint tool. IIUC, it's difficult for a human to notice difference in the time to execute flake8 vs ruff using this project's code base.

My preference for this project is using a minimal set of tool with a minimal set of configurations. I feel the direction of this PR is not much aligned with the direction I want to go...