Use `ruff` for linting/formatting

[antonpirker]

Would be nice to get rid of flake8 and black and only use ruff for all our linting/formatting. To make local development a bit easier and have all the configuration in one place.

mypy is still needed though, because ruff can not replace it.

Currently this is not possible, because ruff does not support type annotations in comments: https://github.com/astral-sh/ruff/issues/1619

So this will be only something we from type annotations in comments to proper type annotations.