Add guard against division by zero in test

- Add assertion to check len(scores) > 0 before calculating average
- Prevents potential ZeroDivisionError if no test cases are run

Co-authored-by: gkorland <753206+gkorland@users.noreply.github.com>

Author: Copilot

tests/test_rag.py

@@ -201,6 +201,7 @@ def test_movie_actor_queries(self, knowledge_graph_setup, delete_kg):
         delete_kg(kg)
 
         # Verify that the average score meets the threshold
+        assert len(scores) > 0, "No scores were collected"
         average_score = sum(scores) / len(scores)
         logger.info(f"Average Score: {average_score}")
         assert average_score >= 0.5, f"Average score {average_score} is below threshold of 0.5"