We install all available official keys in /usr/share but we only enable
those who are relevant for the given architecture. That way we don't
have more keys installed than necessary, and make it easy to enable more
keys if you would like to do crosscompile or run different architecture
via qemu.

Add key for ppc64le builder

remove old/unused eglibc key
added aarch64 builder key

This is we can install a chroot with the keys but wihout pulling in
openrc.