layer1: remove old namespace watcher helpers

pkg/executor/multitenant/ns_watcher.go

@@ -66,7 +66,6 @@ import (
 
 	"go.uber.org/zap"
 	corev1 "k8s.io/api/core/v1"
-	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	k8sInformers "k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
@@ -212,12 +211,3 @@ func registerExecutorTypes(
 	}
 	return joinErr
 }
-
-// namespaceName extracts the namespace name from an informer event object.
-func namespaceName(obj interface{}) string {
-	accessor, err := meta.Accessor(obj)
-	if err != nil {
-		return ""
-	}
-	return accessor.GetName()
-}