fix type of mget

Signed-off-by: BoazBD <boazbd@amazon.com>

python/python/glide/async_commands/server_modules/json.py

@@ -144,7 +144,7 @@ async def mget(
     keys: List[TEncodable],
     paths: Optional[Union[TEncodable, List[TEncodable]]] = None,
     options: Optional[JsonGetOptions] = None,
-) -> Optional[List[bytes]]:
+) -> Optional[List[Optional[bytes]]]:
     """
     Retrieves the JSON values at the specified `paths` stored at multiple `keys`.
 
@@ -179,9 +179,7 @@ async def mget(
             paths = [paths]
         args.extend(paths)
 
-    results = await client.custom_command(args)
-    return [result if result is not None else None for result in results]
-
+    return cast(List[Optional[bytes]], await client.custom_command(args))
 
 async def arrlen(
     client: TGlideClient,