input: Write a python function to remove duplicates from a list.
  assert remove_duplicates(["Python", "Python", "programming", "language", "language"]) == ["Python", "programming", "language"]
  assert remove_duplicates([1, 2, 2, 3, 4, 4, 5]) == [1, 2, 3, 4, 5]
  assert remove_duplicates(["apple", "banana", "apple", "cherry"]) == ["apple", "banana", "cherry"]
output: def remove_duplicates(lst):
      return list(dict.fromkeys(lst))