sage

57b77717 -

gh-36898: ruff auto-fixing several details in combinat folder this was scripted using `ruff --fix --select=UP009,UP018,UP034,UP039,UP025 src/sage/combinat` see https://docs.astral.sh/ruff/rules/#pyupgrade-up ### :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/36898 Reported by: Frédéric Chapoton Reviewer(s): David Coudert