Make WaitForTailscaleLogout a Scenario method

integration/scenario.go

@@ -469,3 +469,19 @@ func (s *Scenario) ListTailscaleClientsFQDNs(namespaces ...string) ([]string, er
 
 	return allFQDNs, nil
 }
+
+func (s *Scenario) WaitForTailscaleLogout() {
+	for _, namespace := range s.namespaces {
+		for _, client := range namespace.Clients {
+			namespace.syncWaitGroup.Add(1)
+
+			go func(c TailscaleClient) {
+				defer namespace.syncWaitGroup.Done()
+
+				// TODO(kradalby): error handle this
+				_ = c.WaitForLogout()
+			}(client)
+		}
+		namespace.syncWaitGroup.Wait()
+	}
+}