style(tests): fix ruff format violations in tdd_langgraph_disposables_steps.py

ISSUES CLOSED: #10398

features/steps/tdd_langgraph_disposables_steps.py

@@ -75,8 +75,7 @@ def step_assert_subscriptions_populated(context: object) -> None:
     # subscription stored.
     subs = context.graph._subscriptions
     assert len(subs) >= len(context.graph.nodes), (
-        f"Expected at least {len(context.graph.nodes)} subscriptions, "
-        f"got {len(subs)}"
+        f"Expected at least {len(context.graph.nodes)} subscriptions, got {len(subs)}"
     )
 
 
@@ -113,8 +112,9 @@ def step_assert_all_disposed(context: object) -> None:
         f"stop() raised unexpectedly: {context.stop_error}"
     )
     for i, mock_disp in enumerate(context.mock_disposables):
-        mock_disp.dispose.assert_called_once(), (
-            f"Disposable #{i} was not disposed by stop()"
+        (
+            mock_disp.dispose.assert_called_once(),
+            (f"Disposable #{i} was not disposed by stop()"),
         )