input: Write a python function to remove all occurrences of a specified number from a list.
  assert remove_all(3, [1, 2, 3, 4, 3, 5, 3]) == [1, 2, 4, 5]
  assert remove_all(10, [10, 20, 30, 10, 40, 10, 50]) == [20, 30, 40, 50]
  assert remove_all(7, [7, 7, 7, 7, 7]) == []
  assert remove_all(2, [1, 2, 3, 4, 5]) == [1, 3, 4, 5]
output: def remove_all(number, lst):
      return [x for x in lst if x != number]