Fix test_system flaky setup_teardown fn

BACKPORT-UPSTREAM=saltstack#66861
DOWNSTREAM-REF=openSUSE/salt#675

tests/pytests/functional/modules/test_system.py

@@ -4,10 +4,12 @@
 import signal
 import subprocess
 import textwrap
+import time
 
 import pytest
 
 import salt.utils.files
+from salt.exceptions import CommandExecutionError
 
 INSIDE_CONTAINER = os.getenv("HOSTNAME", "") == "salt-test-container"
 
@@ -80,7 +82,13 @@ def setup_teardown_vars(file, service, system):
             file.remove("/etc/machine-info")
 
         if _systemd_timesyncd_available_:
-            res = service.start("systemd-timesyncd")
+            try:
+                res = service.start("systemd-timesyncd")
+            except CommandExecutionError:
+                # We possibly did too many restarts in too short time
+                # Wait 10s (default systemd timeout) and try again
+                time.sleep(10)
+                res = service.start("systemd-timesyncd")
             assert res