kube-controller-manager: readjust log verbosity

- Increase the global level for broadcaster's logging to 3 so that users can ignore event messages by lowering the logging level. It reduces information noise.
- Making sure the context is properly injected into the broadcaster, this will allow the -v flag value to be used also in that broadcaster, rather than the above global value.
- test: use cancellation from ktesting
- golangci-hints: checked error return value

pkg/controller/endpointslice/endpointslice_controller.go

@@ -86,7 +86,7 @@ func NewController(ctx context.Context, podInformer coreinformers.PodInformer,
 	client clientset.Interface,
 	endpointUpdatesBatchPeriod time.Duration,
 ) *Controller {
-	broadcaster := record.NewBroadcaster()
+	broadcaster := record.NewBroadcaster(record.WithContext(ctx))
 	recorder := broadcaster.NewRecorder(scheme.Scheme, v1.EventSource{Component: "endpoint-slice-controller"})
 
 	endpointslicemetrics.RegisterMetrics()