Remove duplicate stats keys in quorum queues

Messages, messages_ready and messages_unacknowledged are duplicated
during management stats collection, resulting in internal errors
when sorting queues in the management UI.
These should not be part of rabbit_core_metrics:queue_stats/2

(cherry picked from commit d860efa)

deps/rabbit/src/rabbit_quorum_queue.erl

@@ -581,9 +581,6 @@ handle_tick(QName,
                            {publishers, NumEnqueuers},
                            {consumer_capacity, Util},
                            {consumer_utilisation, Util},
-                           {messages, NumMessages},
-                           {messages_ready, NumReadyMsgs},
-                           {messages_unacknowledged, NumCheckedOut},
                            {message_bytes_ready, EnqueueBytes},
                            {message_bytes_unacknowledged, CheckoutBytes},
                            {message_bytes, MsgBytes},