Switch code formatter from Flake8 to Ruff

[semohr]

This PR updates the project’s code formatting and linting from Flake8 to Ruff.

Ruff should allow faster linting, better type hint support, and more modern rule enforcement, all current checks and configurations have been migrated.

I also added a .git-blame-ignore-revs file which allows ignoring the formatting commit in git blame.

Hope this change is welcome and I'm not overstepping here. Feedback is very welcome!