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