input: Write a function to remove duplicate elements from a list.
  assert deleteDuplicates([1, 2, 2, 3, 4, 4, 5])==[1, 2, 3, 4, 5]
  assert deleteDuplicates([7, 8, 8, 9, 10, 10])==[7, 8, 9, 10]
  assert deleteDuplicates([11, 11, 12, 13, 13, 14])==[11, 12, 13, 14]
output: def deleteDuplicates(lst):
      return list(dict.fromkeys(lst))