input: Write a function to delete the third element of a list.
  assert delete_third_element([1, 2, 3, 4, 5]) == [1, 2, 4, 5]
  assert delete_third_element(['a', 'b', 'c', 'd']) == ['a', 'b', 'd']
  assert delete_third_element([10, 20, 30, 40, 50]) == [10, 20, 40, 50]
output: def delete_third_element(lst):
      if len(lst) >= 3:
          del lst[2]
      return lst