[v3-1-test] Update AI question header to 5th-level in PR template and add separator (#60531)#60556

jscheffl merged 1 commit intov3-1-testapache/airflow:v3-1-testfrom

backport-e061647-v3-1-testapache/airflow:backport-e061647-v3-1-testCopy head branch name to clipboard