Allow force enabling app commands using flag in extras (#6018)

redbot/core/bot.py

@@ -1930,6 +1930,8 @@ class Red(
                 self.dispatch("command_add", subcommand)
                 if permissions_not_loaded:
                     subcommand.requires.ready_event.set()
+        if isinstance(command, (commands.HybridCommand, commands.HybridGroup)):
+            command.app_command.extras = command.extras
 
     def remove_command(self, name: str, /) -> Optional[commands.Command]:
         command = super().remove_command(name)