input: Write a python function to calculate the length of each string in a list and return these lengths.
  assert list_length(["apple", "banana", "cherry"]) == [5, 6, 6]
  assert list_length(["hello", "world"]) == [5, 5]
  assert list_length(["a", "ab", "abc"]) == [1, 2, 3]
output: def list_length(strings):
      return [len(s) for s in strings]