test: load the SELinux module outside of the VM

test: load the SELinux module outside of the VM

Turns out we can, apart from just building the module, "shove" it into
the SELinux database in a chroot as well. This brings quite significant
time savings, as the SELinux db rebuild takes 2 - 5 minutes in a VM
without acceleration (and takes currently ~half of the runtime of the test
in the C8S job).