Replace sage.algebras.yangian.GeneratorIndexingSet with cartesian_product #34375
Description
We replace the GeneratorIndexingSet in yangian.py with cartesian_product, which its implementation is (now) duplicating.
CC: @tscrim
Component: algebra
Author: Travis Scrimshaw
Branch/Commit: abf1edc
Reviewer: Matthias Koeppe
Issue created by migration from https://trac.sagemath.org/ticket/34375