Ruff format tests

[niccokunzmann]

This is a contribution to #672 and formats the test files.

Some errors are still in the tests files. I started with formatting these as they likely do not cause merge conflicts for future contributions.

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📚 Documentation preview 📚: https://icalendar--719.org.readthedocs.build/

[coveralls]

Pull Request Test Coverage Report for Build 11364762185

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 674 of 677 (99.56%) changed or added relevant lines in 41 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.1%) to 97.489%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/icalendar/tests/hypothesis/test_fuzzing.py	6	7	85.71%
src/icalendar/tests/test_cli_tool.py	10	11	90.91%
src/icalendar/tests/test_with_doctest.py	5	6	83.33%

Files with Coverage Reduction	New Missed Lines	%
src/icalendar/caselessdict.py	1	92.41%

Totals
Change from base Build 11364750615:	0.1%
Covered Lines:	3517
Relevant Lines:	3604

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💛 - Coveralls

[niccokunzmann]

@jacadzaca, if you have time, please review it.
@stevepiercy, this is for #672 in which we had a discussion about code styling.

[stevepiercy]

Proper grammar on change log. If tests pass, LGTM!

[niccokunzmann]

@stevepiercy Thanks for the review! When the tests pass, I will merge it.