Merge pull request #57340 from jmcmeek/jmcmeek_57044

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Fix garbage collector when leader-elect=false

**What this PR does / why we need it**:

In a 1.8.x master with --leader-elect=false, the garbage collector controller
does not work.

When deleting a deployment with v1meta.DeletePropagationForeground, the deployment
had its deletionTimestamp set and a foreground Deletion finalizer was added,
but the deployment, rs and pod were not deleted.

This is an issue with how the garbage collector graph_builder behaves when the
stopCh=nil.  This PR creates a dummy stop channel for the garbage collector controller (and other
controllers started by the controller-manager) so that they can work more like they do when
when the controller-manager is configured with --leader-elect=true.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #57044

**Special notes for your reviewer**:

**Release note**:

```release-note
Fix garbage collection when the controller-manager uses --leader-elect=false
```

cmd/kube-controller-manager/app/controllermanager.go

@@ -169,7 +169,9 @@ func Run(s *options.CMServer) error {
 	}
 
 	if !s.LeaderElection.LeaderElect {
-		run(nil)
+		stopCh := make(chan struct{})
+		defer close(stopCh)
+		run(stopCh)
 		panic("unreachable")
 	}