Update test_native_tracer.py

Author: erichare

src/backend/tests/unit/services/tracing/test_native_tracer.py

@@ -703,6 +703,7 @@ def test_empty_input(self):
         result = NativeTracer._topological_sort_spans([])
         assert result == []
 
+
 # ---------------------------------------------------------------------------
 # _flush_to_database with parent/child spans
 # ---------------------------------------------------------------------------