Follow-up on #32411.

Use of floor/ceil from sage.functions can be avoided.

Modules that only need symbolics in some methods should avoid module-level imports from sage.functions, sage.symbolic, sage.calculus.

Doctests that need these modules should be marked # optional - sage.symbolic.

This can be tested using #32601 (sagemath-standard-no-symbolics)

CC: @tscrim

Component: refactoring

Author: Matthias Koeppe

Branch/Commit: 4a1b489

Reviewer: Samuel Lelièvre

Issue created by migration from https://trac.sagemath.org/ticket/32609