fix(system-upgrades): Fix bootloop after system upgrade

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.

infrastructure/system-upgrades/fedora.yaml

@@ -12,7 +12,7 @@ stringData:
     set -x
     dnf install -y dnf-utils
     dnf upgrade -y --best
-    if needs-restarting; then
+    if ! dnf needs-restarting --reboothint; then
       systemctl reboot
     fi
 ---