Migrate from Poetry to UV

[devinmatte]

Migrate our package manager from poetry to UV

We can model the change off of PRs https://github.com/transitmatters/mbta-performance/pull/61 and https://github.com/transitmatters/new-train-tracker/pull/259

Ensure we

• [ ] Swap Poetry with UV
• [ ] Swap Black and Flake8 with Ruff
• [ ] Update vscode settings.json
• [ ] Update extensions.json for vscode
• [ ] Update README (maybe improve it while you're at it)
• [ ] Update all CI
• [ ] Update .gitignore
• [ ] Add pre-commit hook
• [ ] Update pyproject.toml to new format