Investigate alternative to flask

[DavAug]

Below comments from JOSS review:

Certainly not required but ruff is an excellent alternative to Flake8, it covers all the rules Flake8 does, is considerably faster and has a pre-commit hook which can be added and integrated with GitHub Actions via pre-commit.ci. For more on this see Research Software Engineering Sheffield - pre-commit : Protecting your future self.

If you've ever time to work on this I can highly recommend pre-commit and pre-commit.ci the later of which integrates well with a GitHub action and catches instances where contributors might not have applied Flake8 locally before commits (I added some links to more information in a openjournals/joss-reviews#5925 (comment) that may be useful).