input: Write a python function to assign a given value to all elements in a list.
  assert assign_value([2, 3, 4, 5], 7) == [7, 7, 7, 7]
  assert assign_value([1, 2, 3], 0) == [0, 0, 0]
  assert assign_value([10, 20, 30], 5) == [5, 5, 5]
output: def assign_value(lst, value):
      return [value] * len(lst)