World.attach doesn't work for scenario attachments in integration_test.

[vrnvorona]

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  @override
  Future<void> onAfterScenario(
    TestConfiguration config,
    String scenario,
    Iterable<Tag> tags, {
    bool passed = true,
  }) async {
    world.attach(
      world.container.read(failedMocksProvider).join('/n'),
      'text/plain',
    );
  }

I have following Hook (I save world earlier) which doesn't attach anything to the json. In runner only step.onFinished invoke function to get attachments.