Remove rabbit_queue_type:feature_flag_name/1

As this functionality is covered by the rabbit_queue_type:is_enabled/1
API.

deps/rabbit/src/rabbit_queue_type.erl

@@ -20,7 +20,6 @@
          close/1,
          discover/1,
          short_alias_of/1,
-         feature_flag_name/1,
          to_binary/1,
          default/0,
          default_alias/0,
@@ -335,15 +334,6 @@ short_alias_of(<<"stream">>) ->
 short_alias_of(_Other) ->
     undefined.
 
-feature_flag_name(<<"quorum">>) ->
-    quorum_queue;
-feature_flag_name(<<"classic">>) ->
-    undefined;
-feature_flag_name(<<"stream">>) ->
-    stream_queue;
-feature_flag_name(_) ->
-    undefined.
-
 %% If the client does not specify the type, the virtual host does not have any
 %% metadata default, and rabbit.default_queue_type is not set in the application env,
 %% use this type as the last resort.
@@ -374,7 +364,7 @@ to_binary(Other) ->
 
 %% is a specific queue type implementation enabled
 -spec is_enabled(module()) -> boolean().
-is_enabled(Type) ->
+is_enabled(Type) when is_atom(Type) ->
     Type:is_enabled().
 
 -spec is_compatible(module(), boolean(), boolean(), boolean()) ->

deps/rabbit/src/rabbit_vhost.erl

@@ -166,19 +166,18 @@ do_add(Name, Metadata, ActingUser) ->
     case Metadata of
         #{default_queue_type := DQT} ->
             %% check that the queue type is known
-            rabbit_log:debug("Default queue type of virtual host '~ts' is ~tp", [Name, DQT]),
+            rabbit_log:debug("Default queue type of virtual host '~ts' is ~tp",
+                             [Name, DQT]),
             try rabbit_queue_type:discover(DQT) of
-                _ ->
-                    case rabbit_queue_type:feature_flag_name(DQT) of
-                        undefined -> ok;
-                        Flag when is_atom(Flag) ->
-                            case rabbit_feature_flags:is_enabled(Flag) of
-                                true  -> ok;
-                                false -> throw({error, queue_type_feature_flag_is_not_enabled})
-                            end
+                QueueType when is_atom(QueueType) ->
+                    case rabbit_queue_type:is_enabled(QueueType) of
+                        true ->
+                            ok;
+                        false ->
+                            throw({error, queue_type_feature_flag_is_not_enabled})
                     end
             catch _:_ ->
-                throw({error, invalid_queue_type, DQT})
+                      throw({error, invalid_queue_type, DQT})
             end;
         _ ->
             ok