Since the secrets path is only available inside the container, but the
systemd-run command is executed outside the container, it can't access
the secret path, therefore the file needs to be copied.

This patch fixes issues currently faced by longhorn, where the SELinux
policy denies a DAC_override for iscsid. Since I couldn't find on what
file it even tries to do this override, for now, this override to fix
unmountable volumes.

This patch restrict Fedora upgrades to nodes with an explicit label
`upgrade.shivering-isles.com/fedora-35-to-36=true`. This ensures a
controlled transition between versions.

By simply exiting successful, when F36 is already installed, this should
smoothly make this script idempotent enough for current use.

This patch removes the integrated reboot from the upgrade plan, and
replaces it, by a reboot managed by kured.

References:
https://github.com/weaveworks/kured

This patch should just improve the readablity for the matchExpressions a
bit.

Currently various scriptlets fail as part of `dnf upgrade -y` due to
SELinux transitions conflicting with `spc_t`. Which also prevented a
proper kernel update.

Therefore this solution just triggers the right systemd job, that should
take care of the update, before checking if we need to reboot the
machine.

References:
https://danwalsh.livejournal.com/74754.html

This patch resolves the issues with the bootloop caused by the wrong
implementation of `needs-restarting`, which returns a list of apps, that
needs to be restarted. However, without the `--reboothint` parameter,
it'll fail to indicate the reboot requirement using an exit code.

Therefore the loop was always true and resulted in a reboot loop.