Build with --polkit-permissive

This allows us to get rid of the extra pkla rule, makes debugging easier and isn't way more insecure. I hope we get that changed for Debian Bookworm:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=800598

(we're rebuilding MM anyway and will likely do so for some time since there's fixes trickling in (mms,...))