Remove unnecessary return value

Co-authored-by: Ryan McCormick <[email protected]>

src/c++/perf_analyzer/genai-pa/tests/test_cli.py

@@ -96,4 +96,4 @@ def test_arguments_model_not_provided(self):
 
     def test_exception_on_nonzero_exit(self):
         with pytest.raises(GenAiPAException) as e:
-            _ = run(["-m", "nonexistent_model"])
+            run(["-m", "nonexistent_model"])