Don't start goroutine for noMetrics

Problem:
When calling newQueue metrics can be of type noMetrics when just calling
New. When doing this a new goroutine is created to update the metrics
but in this case there are no metrics so it's just creating goroutines
that don't do anything but consume resources.

Solution:
If the incoming metrics is of type noMetrics, don't start the goroutine

Kubernetes-commit: de021396f81ff438899297a6f464c70113b58475

util/workqueue/queue.go

@@ -55,7 +55,13 @@ func newQueue(c clock.Clock, metrics queueMetrics, updatePeriod time.Duration) *
 		metrics:                    metrics,
 		unfinishedWorkUpdatePeriod: updatePeriod,
 	}
-	go t.updateUnfinishedWorkLoop()
+
+	// Don't start the goroutine for a type of noMetrics so we don't consume
+	// resources unnecessarily
+	if _, ok := metrics.(noMetrics); !ok {
+		go t.updateUnfinishedWorkLoop()
+	}
+
 	return t
 }