Merge pull request #69550 from tallclair/runtimeclass-spec

cluster/addons/runtimeclass/runtimeclass_crd.yaml

@@ -23,4 +23,4 @@ spec:
           properties:
             runtimeHandler:
               type: string
-              pattern: '^[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$'
+              pattern: '^([a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*)?$'