input: Write a Python function to order dictionary items based on the product of the tuple keys for the given dictionary.
  assert order_dict_by_tuple_product({(5, 6): 3, (2, 3): 9, (8, 4): 10, (6, 4): 12}) == {(2, 3): 9, (6, 4): 12, (5, 6): 3, (8, 4): 10}
  assert order_dict_by_tuple_product({(6, 7): 4, (3, 4): 10, (9, 5): 11, (7, 5): 13}) == {(3, 4): 10, (7, 5): 13, (6, 7): 4, (9, 5): 11}
  assert order_dict_by_tuple_product({(7, 8): 5, (4, 5): 11, (10, 6): 12, (8, 6): 14}) == {(4, 5): 11, (8, 6): 14, (7, 8): 5, (10, 6): 12}
output: def order_dict_by_tuple_product(d):
      return dict(sorted(d.items(), key=lambda item: item[0][0] * item[0][1]))