build: set up formatting and linting

[koebi]

Following the discussion, we decided to use ruff as a linter/autoformatter.

Configuration only excludes autogenerated files and sets line length to 100.

Fixes #141

[TheGreatRefrigerator]

Finnaly had the chance to test this out locally. Everything works fine.

3 Things from my side:

1: Would squash the first 3 commits and tag as type ci instead of build as it's GH actions.

2: drop bb87a1b & 2bde6ac as it's + x - x

3: I remember some issues todo with a missing resources_rc, maybe double check that removing the from . import resources_rc from ORSToolsDialog.py won't cause issues after e.g. recompiling resources.qrc. But prob. it's fine.

[TheGreatRefrigerator]

Looks good