[Menus] Handle ctx.me that can be None when clearing reactions (#3902)

redbot/core/utils/menus.py

@@ -94,6 +94,8 @@ async def menu(
             timeout=timeout,
         )
     except asyncio.TimeoutError:
+        if not ctx.me:
+            return
         try:
             if message.channel.permissions_for(ctx.me).manage_messages:
                 await message.clear_reactions()