sage

23d371a7 -

gh-41092: tweak annotations for cachefunc so that mypy does not complain ### :memo: Checklist - [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/41092 Reported by: Frédéric Chapoton Reviewer(s): Tobias Diez