tests/int/delete: make sure runc delete removes failed unit

The passing run (with the fix) looks like this:

----
delete.bats
 ✓ runc delete removes failed systemd unit [4556]
   runc spec (status=0):

   runc run -d --console-socket /tmp/bats-run-B08vu1/runc.lbQwU5/tty/sock test-failed-unit (status=0):

   Warning: The unit file, source configuration file or drop-ins of runc-cgroups-integration-test-12869.scope changed on disk. Run 'systemctl daemon-reload' to reload units.
   × runc-cgroups-integration-test-12869.scope - libcontainer container integration-test-12869
        Loaded: loaded (/run/systemd/transient/runc-cgroups-integration-test-12869.scope; transient)
     Transient: yes
       Drop-In: /run/systemd/transient/runc-cgroups-integration-test-12869.scope.d
                └─50-DevicePolicy.conf, 50-DeviceAllow.conf
        Active: failed (Result: timeout) since Tue 2023-06-13 14:41:38 PDT; 751ms ago
      Duration: 2.144s
           CPU: 8ms

   Jun 13 14:41:34 kir-rhat systemd[1]: Started runc-cgroups-integration-test-12869.scope - libcontainer container integration-test-12869.
   Jun 13 14:41:37 kir-rhat systemd[1]: runc-cgroups-integration-test-12869.scope: Scope reached runtime time limit. Stopping.
   Jun 13 14:41:38 kir-rhat systemd[1]: runc-cgroups-integration-test-12869.scope: Stopping timed out. Killing.
   Jun 13 14:41:38 kir-rhat systemd[1]: runc-cgroups-integration-test-12869.scope: Killing process 1107438 (sleep) with signal SIGKILL.
   Jun 13 14:41:38 kir-rhat systemd[1]: runc-cgroups-integration-test-12869.scope: Failed with result 'timeout'.
   runc delete test-failed-unit (status=0):

   Unit runc-cgroups-integration-test-12869.scope could not be found.
----

Before the fix, the test was failing like this:

----
delete.bats
 ✗ runc delete removes failed systemd unit
   (in test file tests/integration/delete.bats, line 194)
     `run -4 systemctl status "$SD_UNIT_NAME"' failed, expected exit code 4, got 3
  ....
----

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

tests/integration/delete.bats

@@ -168,3 +168,30 @@ EOF
 	# check delete subcgroups success
 	[ ! -d "$CGROUP_V2_PATH"/foo ]
 }
+
+@test "runc delete removes failed systemd unit" {
+	requires systemd_v244 # Older systemd lacks RuntimeMaxSec support.
+
+	set_cgroups_path
+	# shellcheck disable=SC2016
+	update_config '	  .annotations += {
+				"org.systemd.property.RuntimeMaxSec": "2",
+				"org.systemd.property.TimeoutStopSec": "1"
+			   }
+			| .process.args |= ["/bin/sleep", "10"]'
+
+	runc run -d --console-socket "$CONSOLE_SOCKET" test-failed-unit
+	[ "$status" -eq 0 ]
+
+	wait_for_container 10 1 test-failed-unit stopped
+
+	local user=""
+	[ $EUID -ne 0 ] && user="--user"
+
+	# Expect "unit is not active" exit code.
+	run -3 systemctl status $user "$SD_UNIT_NAME"
+
+	runc delete test-failed-unit
+	# Expect "no such unit" exit code.
+	run -4 systemctl status $user "$SD_UNIT_NAME"
+}