Enables DisableKubeletCloudCredentialProviders feature gate

Enables the DisableKubeletCloudCredentialProviders feature gate

Cloud credential providers for AWS, GCP and Azure are now functional. We
can disable the in tree kubelet providers.

config/v1/feature_gates.go

@@ -432,6 +432,7 @@ var (
 								reportProblemsToJiraComponent("cloud-provider").
 								contactPerson("jspeed").
 								productScope(kubernetes).
+								enableIn(Default, TechPreviewNoUpgrade).
 								mustRegister()
 
 	FeatureGateOnClusterBuild = newFeatureGate("OnClusterBuild").