input: Write a python function to merge two sorted lists into a single sorted list without duplicates.
  assert merge_unique_sorted_lists([1, 2, 3], [2, 3, 4]) == [1, 2, 3, 4]
  assert merge_unique_sorted_lists([5, 6, 7], [7, 8, 9]) == [5, 6, 7, 8, 9]
  assert merge_unique_sorted_lists([10, 20, 30], [20, 40, 50]) == [10, 20, 30, 40, 50]
output: def merge_unique_sorted_lists(list1, list2):
      merged_list = sorted(set(list1 + list2))
      return merged_list