sage

e0b30f98 -

gh-38497: minor details in categories folder just a few minor fixes in the `categories` folder (pyx files) ### :memo: Checklist <!-- Put an `x` in all the boxes that apply. --> - [x] The title is concise and informative. - [x] The description explains in detail what this PR is about. URL: https://github.com/sagemath/sage/pull/38497 Reported by: Frédéric Chapoton Reviewer(s):