input: Write a function to remove all occurrences of a specified item from a list.
  assert remove_item([1, 4, 8, 2], 8) == [1, 4, 2]
  assert remove_item([1, 2, 3, 4, 2, 2, 5], 2) == [1, 3, 4, 5]
  assert remove_item([6, 7, 6, 6, 7, 8, 9], 6) == [7, 7, 8, 9]
output: def remove_item(lst, item):
      return [i for i in lst if i != item]