CLN: remove unnecessary values_from_objects in groupby.ops (#32547)

Author: jbrockmendel

pandas/core/groupby/ops.py

@@ -217,7 +217,7 @@ def indices(self):
             return self.groupings[0].indices
         else:
             codes_list = [ping.codes for ping in self.groupings]
-            keys = [com.values_from_object(ping.group_index) for ping in self.groupings]
+            keys = [ping.group_index for ping in self.groupings]
             return get_indexer_dict(codes_list, keys)
 
     @property