We move writing of the default.qepcadrc file from sage-location (where it is the last productive bit) to the installation file.

CC: @kiwifb @embray @sagetrac-felixs @jdemeyer @fchapoton @jhpalmieri @dimpase

Component: packages: optional

Author: Matthias Koeppe

Branch/Commit: 3e40ee8

Reviewer: John Palmieri

Issue created by migration from https://trac.sagemath.org/ticket/21783