gh-36623: cylint cleanup in combinatorial polyhedra
fixes all cython-lint warnings in combinatorial_polyhedron folder
### :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/36623
Reported by: Frédéric Chapoton
Reviewer(s): Kwankyu Lee
