chore: Replace black, isort, flak8 and autoflake by ruff

[schwarbf]

This PR aims to close the open issue 453.

I tried to do as little code changes as possible. I did the following:

• I started taking the ruff config from the docling repository
• Using ruff now as a replacement for black, isort, autoflake and flake8
• Ran ruff format (formatted approx. 30 files) and ruff check --fix (fixed approx. 50 warnings)
• Excluded the test/data from ruff
• Added some rules to the ignore list that would have affected > 3 changes. Feel free to remove any again to see possible changes.
• Set the line length again to 120 in pyproject.toml (was 120 in .flake8 file, but 88 in pyproject.toml)

FYI: When checking which commit added ruff to docling, you can see that 5458a88
also changed a significant number of files and added some rules to the ignore list.

[github-actions]

✅ DCO Check Passed

Thanks @schwarbf, all your commits are properly signed off. 🎉

[dosubot]

Related Documentation

Checked 7 published document(s) in 1 knowledge base(s). No updates required.

^{How did I do? Any feedback?}  

[mergify]

Merge Protections

Your pull request matches the following merge protections and will not be merged until they are valid.

🔴 Require two reviewer for test updates

This rule is failing.

When test data is updated, we require two reviewers

• #approved-reviews-by >= 2

🟢 Enforce conventional commit

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Make sure that we follow https://www.conventionalcommits.org/en/v1.0.0/

• title ~= ^(fix|feat|docs|style|refactor|perf|test|build|ci|chore|revert)(?:\(.+\))?(!)?:

[ceberam]

Was this suggested by Ruff?
We still support 3.9 (it may change at some point) and the | syntax is only valid from 3.10. We should therefore keep typing.Optional

[schwarbf]

Okay I see. It's weird since I had actually set :

[tool.ruff]
target-version = "py39"

Anyways, I will revert this part.

[schwarbf]

@ceberam PR should be ready. Let me know if you want me to rebase or merge with docling-core:main or if you want to do it yourself?