input: Write a function to sort words in a list by their length.
  assert sort_words_by_length(["I", "am", "all", "ears"])==["I", "am", "all", "ears"]
  assert sort_words_by_length(["apple", "pie", "is", "delicious"])==["is", "pie", "apple", "delicious"]
  assert sort_words_by_length(["hello", "hi", "hey"])==["hi", "hey", "hello"]
output: def sort_words_by_length(words):
      return sorted(words, key=len)