Since there's a bunch of CPU hungry systemd-journal-remote processes
running on the host to received the forwarded logs, by running as many
test as the VM has cores we overload the available resources. Let's leave
use the number of cores - 1 to reduce resource contention.
Direct kernel boot results in much faster boot times so let's use
it by default.
We disable it for tests that need to reboot because +-50% of the
time, doing a reboot when using direct kernel boot causes qemu to
hang on reboot. Until we figure that out, let's use UEFI for the
tests that need to reboot.
For some reason this fails on ext4 with "No space left on device".
Until we figure out why, let's skip the test on ext4 (which is reported
as ext2/ext3 by stat).
This module is builtin on ubuntu causing the test to fail. Let's
use just dummy instead. I tried replacing it with scsi_debug but
that caused issues with modprobe complaining it could not remove
scsi_debug because it was in use.
When root authorized keys are provided by mkosi they are not
newline-terminated so appending a public key to the file results
in a corrupt key, so just to be safe we add an empty line.
Depending on host configuration this may or may not be included (e.g.
on mkosi we get a result without an ifindex field). Let's strip it from
the resolved reply to avoid failing the test.
