sage.combinat.designs: Use MixedIntegerLinearProgram.get_values options convert, tolerance #32218
Description
Part of #32191 (Meta-ticket: Audit/fix all uses of MixedIntegerLinearProgram in sage.combinat, sage.graphs)
Depends on #32197
CC: @dimpase @dcoudert @tscrim
Component: combinatorics
Author: Matthias Koeppe
Branch/Commit: 5af993f
Reviewer: David Coudert
Issue created by migration from https://trac.sagemath.org/ticket/32218