rabbit_{mnesia,khepri}: Skip generic compat check if CheckNodesConsistency is false

[Why]
`CheckNodesConsistency` is set to false when the
`check_cluster_consistency()` is called as part of a node joining a
cluster. And the generic compatibility check was already executed by
`rabbit_db_cluster`.

There is no need to run it again. This is even counter-productive with
the improvement to `rabbit_feature_flags:check_node_compatibility/2`
that follows.

Author: dumbbell

deps/rabbit/src/rabbit_khepri.erl

@@ -871,10 +871,7 @@ check_cluster_consistency(Node, CheckNodesConsistency) ->
                     Error
             end;
         {_OTP, _Rabbit, {ok, Status}} ->
-            case rabbit_db_cluster:check_compatibility(Node) of
-                ok    -> {ok, Status};
-                Error -> Error
-            end
+            {ok, Status}
     end.
 
 remote_node_info(Node) ->

deps/rabbit/src/rabbit_mnesia.erl

@@ -726,10 +726,7 @@ check_cluster_consistency(Node, CheckNodesConsistency) ->
                     Error
             end;
         {_OTP, _Rabbit, _Protocol, {ok, Status}} ->
-            case rabbit_db_cluster:check_compatibility(Node) of
-                ok    -> {ok, Status};
-                Error -> Error
-            end
+            {ok, Status}
     end.
 
 remote_node_info(Node) ->