TaskGroup “Downstream Clear” doesn’t affect all failed tasks inside the group

### Apache Airflow version 3.1.0 ### If "Other Airflow 2/3 version" selected, which one? _No response_ ### What happened? When I click Downstream Clear on a TaskGroup that contains multiple failed tasks, only a subset of tasks inside the group appear in the “affected tasks” dialog. However, when I click Run → failed only from the DAG Run view, all failed tasks are properly selected and cleared. So, the “Downstream Clear” behavior seems inconsistent between the DAG Run and TaskGroup levels. ### What you think should happen instead? _No response_ ### How to reproduce Create a DAG with many tasks inside a TaskGroup A. Run the DAG and let several tasks in the group fail. Then click the TaskGroup and choose Downstream Clear — only some failed tasks appear in the affected tasks list. In contrast, clicking the DAG Run and choosing Run → failed only correctly selects all failed tasks. ### Operating System Ubuntu 22.04 ### Versions of Apache Airflow Providers _No response_ ### Deployment Official Apache Airflow Helm Chart ### Deployment details _No response_ ### Anything else? _No response_ ### Are you willing to submit PR? - [ ] Yes I am willing to submit a PR! ### Code of Conduct - [x] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)