Remove special handling for 404 response from K8s

There is no reason to specially handle 404 here. We only handle 404
specifically if we are fetching something and want to return `nil` if
404.  This does not apply here.

app/services/clusters/gcp/kubernetes/create_or_update_namespace_service.rb

@@ -16,8 +16,6 @@ module Clusters
           configure_kubernetes_token
 
           kubernetes_namespace.save!
-        rescue ::Kubeclient::HttpError => err
-          raise err unless err.error_code = 404
         end
 
         private