fixed type hint of hrandfield method

Signed-off-by: amirreza <amir.rsf1380@gmail.com>

valkey/commands/core.py

@@ -2153,7 +2153,7 @@ def pttl(self, name: KeyT) -> ResponseT:
 
     def hrandfield(
         self, key: str, count: int = None, withvalues: bool = False
-    ) -> ResponseT:
+    ) -> bytes | list[bytes] | None:
         """
         Return a random field from the hash value stored at key.