Run ruff, add to precommit

[pamelafox]

Purpose

This PR runs ruff, an industry standard linter, over all Python files. It also adds it to pre-commit hooks and GitHub actions.

Does this introduce a breaking change?

[ ] Yes
[X] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[ ] Feature
[X] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

Run app/start.sh, local server should be fine.