sage.rings.all has a mixture of generic classes and implementation classes. Some of the generic and/or basic ones will probably have to be included in sage-objects (#29865). We prepare this by getting rid of imports from sage.rings.all throughout sage.categories.

CC: @tscrim

Component: refactoring

Author: Matthias Koeppe

Branch/Commit: 82676e6

Reviewer: Travis Scrimshaw, Frédéric Chapoton

Issue created by migration from https://trac.sagemath.org/ticket/29881