I tested this with 'sudo dnf --installroot=…', with both
systemd+system-udev installed in one transaction, and in two separate
transactions. Users are created as expected in both cases.
sysctl, binfmt, and other rules are collected from multiple packages
and we don't want to see a report that systemd %triggerin failed.
So let's not silence the output, but use "|| :" to the trigger is
not reported as failed.
Also, adjust the udevadm check. In containers udevd might not be
running, even if systemd is, and we'd get:
Failed to send reload request: No such file or directory
https://bugzilla.redhat.com/show_bug.cgi?id=1698391
