gh-36474: add ruff to developer tools
This is just adding the fast linter `ruff` to the developer guide as yet
another of our tools-of-the-trade.
### :memo: Checklist
- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
URL: https://github.com/sagemath/sage/pull/36474
Reported by: Frédéric Chapoton
Reviewer(s): Kwankyu Lee
