docs: fix rtd build that broke in #828 (#849)

Author: Toricane

interactions/api/models/channel.py

@@ -714,7 +714,7 @@ async def get_message(
     async def purge(
         self,
         amount: int,
-        check: Callable[[...], bool] = MISSING,
+        check: Callable[[Any], bool] = MISSING,
         before: Optional[int] = MISSING,
         reason: Optional[str] = None,
         bulk: Optional[bool] = True,