Add CBOR feature gates.

For alpha, there is one apiserver feature gate and two client-go feature gates controlling
CBOR. They were initially wired to separate test-only feature gate instances in order to prevent
them from being configurable at runtime via command-line flags or environment variables (for
client-go feature gates outside of Kubernetes components). All of the integration tests required by
the KEP as alpha criteria have been implemented. This adds the feature gates to the usual feature
gate instances and removes the temporary code to support separate test-only feature gate instances.

pkg/features/client_adapter.go

@@ -67,3 +67,10 @@ func (a *clientAdapter) Add(in map[clientfeatures.Feature]clientfeatures.Feature
 	}
 	return a.mfg.Add(out)
 }
+
+// Set implements the unexported interface that client-go feature gate testing expects for
+// ek8s.io/client-go/features/testing.SetFeatureDuringTest. This is necessary for integration tests
+// to set test overrides for client-go feature gates.
+func (a *clientAdapter) Set(name clientfeatures.Feature, enabled bool) error {
+	return a.mfg.SetFromMap(map[string]bool{string(name): enabled})
+}

pkg/features/versioned_kube_features.go

@@ -245,6 +245,10 @@ var defaultVersionedKubernetesFeatureGates = map[featuregate.Feature]featuregate
 		{Version: version.MustParse("1.32"), Default: true, PreRelease: featuregate.Beta},
 	},
 
+	genericfeatures.CBORServingAndStorage: {
+		{Version: version.MustParse("1.32"), Default: false, PreRelease: featuregate.Alpha},
+	},
+
 	genericfeatures.ConcurrentWatchObjectDecode: {
 		{Version: version.MustParse("1.31"), Default: false, PreRelease: featuregate.Beta},
 	},