Nice work! However, I don't see myself reviewing this in it's current form. There's way to much in a single PR.

Especially because ideally, the formatting changes will be added into the git-blame-ignore-revs file, and this is not possible in its current form as we use squash and merge.

I think this could be split into separate PRs, roughly:

• Add ruff configuration in our pyproject.toml, but only enable formatting:

[tool.ruff]
line-length = "..."
extend-exclude = ["..."]  # Not sure if any extra excludes is required

• In a separate PR, enable ruff format and remove black in the pre-commit config, apply formatting changes, merge.
• In a separate PR, add the previous commit sha into the ignored blame revs.
• Start adding lint:
  • Switch from isort to Ruff's isort (if too many changes, do the same as for formatting, and add the commit sha in the ignored blame revs).
  • Continue by adding pyflakes, pycodestyle, ruff, pyupgrade, etc. Preferably in separate PRs, so that we can ignore some commit SHAs if necessary

I was thinking of that. My only real thought was that pre-commit ci would try to autofix and create a bigger difference than necessary (as originally, I just wanted one PR for pyproject/pre-commit changes and another PR for the diff).

Doesn't hurt to try, I'll see what happens

My only real thought was that pre-commit ci would try to autofix and create a bigger difference than necessary (as originally, I just wanted one PR for pyproject/pre-commit changes and another PR for the diff).

Yep, for this, you can add the necessary ruff configuration as I described, and then in a follow up PR make the change in the pre-commit file and let format everything (or let pre-commit do it)

I'll just use this PR as a tracking PR then.
EDIT: Moved to the relevant issue