ci: Speed up python linting

[Fogapod]

This speeds up linting step by ~10 seconds in total.
There are 3 primary changes:

pre-commit caching

pre-commit docs have an example of github caching which i applied: https://pre-commit.com/#github-actions-example

caching python dependencies

uv sync dependencies will now be cached by disabling pruning: prune-cache: false.
I think you would need to remove setup-uv-* caches at https://github.com/DS4SD/docling-serve/actions/caches for this to apply. updated lock file will create new cache

Switching to pre-commit-uv

https://github.com/tox-dev/pre-commit-uv is a patch to pre-commit which uses uv internally which speeds up initial dependency installation. Their caching/configuration is identical, the only change is package installation machinery.
Currently it will be automatically installed as a dev dependency.

I can exclude this patch if this is not desirable

[mergify]

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