Installing any optional package on the binary distribution triggers full recompile of sagelib #29055
Description
https://github.com/mkoeppe/sage-numerical-backends-coin/blob/master/tox.ini
with tox -e docker-sage_binary-cbc_spkg.
https://github.com/mkoeppe/sage-numerical-backends-coin/blob/master/Dockerfile-sage_binary
https://github.com/mkoeppe/sage-numerical-backends-coin/blob/master/Dockerfile-cbc_spkg
CC: @vbraun @dimpase @jdemeyer @embray
Component: build
Reviewer: Dima Pasechnik
Issue created by migration from https://trac.sagemath.org/ticket/29055