Fix mis-name

Author: Middledot

discord/guild.py

@@ -3025,7 +3025,7 @@ async def edit_welcome_screen(
         self,
         *,
         description: Optional[str] = ...,
-        welcome_channels: Optional[List[WelcomeChannel]] = ...,
+        welcome_channels: Optional[List[WelcomeScreenChannel]] = ...,
         enabled: Optional[bool] = ...,
     ) -> WelcomeScreen:
         ...