Make local_branches OPT_OUT

lib/gitlab/git/repository.rb

@@ -166,7 +166,7 @@ module Gitlab
       end
 
       def local_branches(sort_by: nil)
-        gitaly_migrate(:local_branches) do |is_enabled|
+        gitaly_migrate(:local_branches, status: Gitlab::GitalyClient::MigrationStatus::OPT_OUT) do |is_enabled|
           if is_enabled
             gitaly_ref_client.local_branches(sort_by: sort_by)
           else