Draft: fix(arch-nspawn): clean all existing makepkg conf.d files before overriding

This needs thinking and discussion:

• if we simply remove these files, this may create undesired effects (f.e. downstream) when a chroot just wants to replace the single makepkg.conf file instead of removing all chroot working dir conf.d files
• maybe consider adding an option to achieve the new behavior? -m and -M for remove and append

marked this merge request as draft