$ git grep 'functions.*import.*sqrt' finds a small number of these imports

sqrt is actually not a symbolic function, so we move it to sage.misc.functional and import it from there. isqrt already lives there.

(Alternatively, many uses of the sqrt function could be replaced by a call to the .sqrt method.)

Either way will avoid the dependency on sage.symbolic.

(Same for ceil, floor, but that could also be done via #25827.)

CC: @tscrim

Component: refactoring

Author: Matthias Koeppe

Branch/Commit: 451ac27

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/32717