ci: added pre-commit (#811)

This PR introduces a pre-commit config which is used in our ci pipeline.
Furthermore, an additional formatting of all affected resources was
done.

The following config was used as a baseline:
https://github.com/hetznercloud/.github/blob/main/.pre-commit-config.yaml



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Co-authored-by: Jonas L. <jooola@users.noreply.github.com>