Add missing Union type in method StreamCommands.xclaim() (#2553)

`Union` was missing in front of `[List[StreamIdT], Tuple[StreamIdT]]` and VSCode was producing an error because of it.
After adding `Union` the type annotation is correctly identified by VSCode.

Author: ant1fact

redis/commands/core.py

@@ -3551,7 +3551,7 @@ def xclaim(
         groupname: GroupT,
         consumername: ConsumerT,
         min_idle_time: int,
-        message_ids: [List[StreamIdT], Tuple[StreamIdT]],
+        message_ids: Union[List[StreamIdT], Tuple[StreamIdT]],
         idle: Union[int, None] = None,
         time: Union[int, None] = None,
         retrycount: Union[int, None] = None,