Stop getting the K8s version of target cluster in uninstall mode

The target Kubernetes cluster may not be up and running at the time of
uninstall, so don't bother getting cluster version information.

This also stops nsSelMgr.Start from being called when being uninstalled.

Relates:
https://issues.redhat.com/browse/ACM-8826

Signed-off-by: mprahl <mprahl@users.noreply.github.com>

main.go

@@ -357,6 +357,7 @@ func main() {
 	instanceName, _ := os.Hostname() // on an error, instanceName will be empty, which is ok
 
 	var nsSelReconciler common.NamespaceSelectorReconciler
+	var dryRunSupported bool
 
 	if !beingUninstalled {
 		nsSelReconciler = common.NamespaceSelectorReconciler{
@@ -366,24 +367,24 @@ func main() {
 			log.Error(err, "Unable to create controller", "controller", "NamespaceSelector")
 			os.Exit(1)
 		}
-	}
 
-	discoveryClient := discovery.NewDiscoveryClientForConfigOrDie(targetK8sConfig)
+		discoveryClient := discovery.NewDiscoveryClientForConfigOrDie(targetK8sConfig)
 
-	serverVersion, err := discoveryClient.ServerVersion()
-	if err != nil {
-		log.Error(err, "unable to detect the managed cluster's Kubernetes version")
-		os.Exit(1)
-	}
+		serverVersion, err := discoveryClient.ServerVersion()
+		if err != nil {
+			log.Error(err, "unable to detect the managed cluster's Kubernetes version")
+			os.Exit(1)
+		}
 
-	dryRunSupported := semver.Compare(serverVersion.GitVersion, "v1.18.0") >= 0
-	if dryRunSupported {
-		log.Info("The managed cluster supports dry run API requests")
-	} else {
-		log.Info(
-			"The managed cluster does not support dry run API requests. Will assume that empty values are equal to " +
-				"not being set.",
-		)
+		dryRunSupported = semver.Compare(serverVersion.GitVersion, "v1.18.0") >= 0
+		if dryRunSupported {
+			log.Info("The managed cluster supports dry run API requests")
+		} else {
+			log.Info(
+				"The managed cluster does not support dry run API requests. Will assume that empty values are equal " +
+					"to not being set.",
+			)
+		}
 	}
 
 	reconciler := controllers.ConfigurationPolicyReconciler{
@@ -500,7 +501,7 @@ func main() {
 		wg.Done()
 	}()
 
-	if opts.targetKubeConfig != "" { // "hosted mode"
+	if !beingUninstalled && opts.targetKubeConfig != "" { // "hosted mode"
 		wg.Add(1)
 
 		go func() {