display commit under metadata header for DAGs

### Description ### Use case/motivation airflow: 3 context: * when i make a deployment, i want to know whether the DAG referenced by airflow is using the latest commit. * currently, the commit is being shown under "description" - this was manually added by our platform team (@rloredo @OscarLigthart) * this is inefficient because it requires me to click into "details" to see it. solution: * promote "commit version" to the header. request: * what do we think? would this be useful? * any considerations? (yes, maybe not everyone uses git?) <img width="2082" height="522" alt="Image" src="https://github.com/user-attachments/assets/cfd77112-1fc5-4f90-a5c0-c06361198669" /> ### Are you willing to submit a 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)