input: Write a function to remove all the values in a list that are greater than a given value.
  assert remove_greater([10, 15, 20, 25, 30], 15) == [10, 15]
  assert remove_greater([5, 7, 8, 12, 19, 22], 10) == [5, 7, 8]
  assert remove_greater([1, 2, 3, 4, 5], 3) == [1, 2, 3]
output: def remove_greater(lst, value):
      return [x for x in lst if x <= value]