input: Write a function to reverse a list of numbers.
  assert reverse_list([1, 2, 3, 4, 5]) == [5, 4, 3, 2, 1]
  assert reverse_list([10, 20, 30, 40]) == [40, 30, 20, 10]
  assert reverse_list([7, 8, 9]) == [9, 8, 7]
output: def reverse_list(numbers):
      return numbers[::-1]