gh-36853: various details in algebras (ruff mostly)
some details suggested by `ruff` about list and set comprehensions, also
about unicode
### :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/36853
Reported by: Frédéric Chapoton
Reviewer(s): Matthias Köppe
