Use resolvectl, not systemd-resolve

As per:
https://bugs.debian.org/990495

systemd-resolve is deprecated and replaced by resolvectl. Let's
fix this, as no modern distribution should be using the old version.

Change-Id: I3852da0866d988a571a88d070d5410eb158d2688

rally_openstack/task/scenarios/vm/vmtasks.py

@@ -600,7 +600,7 @@ class CheckDesignateDNSResolving(vm_utils.VMScenario):
             key_name=self.context["user"]["keypair"]["name"],
             **kwargs)
 
-        script = f"cloud-init status -w; systemd-resolve --status; "\
+        script = f"cloud-init status -w; resolvectl status; "\
                  f"dig $(hostname).{zone}"
 
         command = {