Update app.py

app.py

@@ -107,7 +107,7 @@ def load_answer_sheet(filepath: str = "answer_sheet.json") -> Dict[str, str]:
         return {}
 
 
-def check_answer_correctness(submitted: str, correct: str) -> Tuple[bool, str]:
+def check_answer_correctness(submitted: str, correct: str) -> tuple[bool, str]:
     """
     Check if submitted answer matches correct answer with fuzzy matching
     Returns: (is_correct, feedback_message)