Update mismatched_return_type_example.py

Added type for list

Author: dphoenix

type-hint-arrow-samples/mismatched_return_type_example.py

@@ -1,6 +1,7 @@
-def get_number_of_titles(titles: list) -> str:
+def get_number_of_titles(titles: list[str]) -> str:
     return len(titles)
 
 
 games = ["Dragon Quest", "Final Fantasy", "Age of Empires"]
 print(f"Number of titles: {get_number_of_titles(games)}")
+