feat(update): update the backend like nodes via quadlet restart [CI]

packaging/systemd/moshiro-backend-container.service

@@ -1,16 +0,0 @@
-[Unit]
-Description=MoShiro Backend (signed container updates)
-After=network-online.target
-Wants=network-online.target
-
-[Service]
-EnvironmentFile=/etc/moshiro-update/backend.image
-Restart=always
-RestartSec=5
-TimeoutStopSec=30
-ExecStartPre=-/usr/bin/podman rm -f moshiro-backend
-ExecStart=/usr/bin/podman run --rm --name moshiro-backend --network host -e ASPNETCORE_URLS=http://0.0.0.0:29181 --read-only --tmpfs /tmp --security-opt no-new-privileges --cap-drop all --env-file /etc/moshiro/backend.env -v moshiro-backend-data:/data -v moshiro-backend-status:/data/update-status:ro ${IMAGE}
-ExecStop=/usr/bin/podman stop -t 20 moshiro-backend
-
-[Install]
-WantedBy=multi-user.target