input: Write a function to remove elements greater than a specified value.
  assert remove_greater_than([1, 2, 3, 4, 5], 3) == [1, 2, 3]
  assert remove_greater_than([10, 20, 30, 40, 50], 25) == [10, 20]
  assert remove_greater_than([5, 15, 25, 35], 20) == [5, 15]
output: def remove_greater_than(lst, value):
      return [x for x in lst if x <= value]