Attribution cleanup

[Zeitsperre]

Pull Request Checklist:

• This PR addresses an already opened issue (for bug fixes / features)
  • This PR fixes #xyz
• (If applicable) Documentation has been added / updated (for bug fixes / features).
• (If applicable) Tests have been added.
• CHANGELOG.rst has been updated (with summary of main changes).

What kind of change does this PR introduce?

• Removes the obsolete MANIFEST.in file
• Adds a few more checks to the pre-commit-hooks
• Updates the authors and maintainers listing in the package metadata
• Updates the contributors listed in the licensing
• Adds Zenodo information for all contributors

Does this PR introduce a breaking change?

No.

Other information:

Some of the checks added are very reasonable, e.g.

• no manual committing to main
• test files and functions should start with the word "test_"
• JSON files should be reformatted (excluding Jupyter Notebooks)
• debug functions should not be found in the library codebase
• remove the UTF-8 byte order marker

[coveralls]

coverage: 91.034%. remained the same
when pulling 565c9ec on attribution-cleanup
into ef3f1f0 on main.