```release-note:enhancement
resource/aws_ssm_maintenance_window_task: Add `arn` and `window_task_id` attributes.
```

```release-note:enhancement
resource/aws_ssm_maintenance_window_task: Add `cutoff_behavior` argument.
```

```release-note:bug
resource/aws_ssm_maintenance_window_task: Allow creating a window taks without targets.
```