Update cookiecutter, mark dead code

[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).
  • Link to issue (:issue:number) and pull request (:pull:number) has been added.

What kind of change does this PR introduce?

• Updates the cookiecutter template to the latest commit
• The CodeQL configuration has been replaced with a newer base template
• Adds two new hooks to pre-commit:
  • vulture: for finding dead code blocks
  • zizmor: for finding insecure workflow configurations

Does this PR introduce a breaking change?

No. Function call signatures have not been changed.

Other information:

Lots of a FIXME notices have been added for unused call signature variables. These should be addressed in the next major release.

mypy is staged, but the code base is far from being able to adopt it. We need to address a lot of typing issues.

I think we can safely tag a new version after this PR is merged.

[coveralls]

coverage: 81.288% (-0.004%) from 81.292%
when pulling b905fa7 on cruft
into a307918 on master.

[tlvu]

LGTM