Multi-Team: list endpoints return resources from all teams regardless of user's team

### Under which category would you file this issue? Providers ### Apache Airflow version 3.3.0 ### What happened and how to reproduce it? With `core.multi_team=True` and the Keycloak auth manager, `GET /api/v2/dags`, `GET /api/v2/variables` and `GET /api/v2/connections` return resources belonging to every team, regardless of the requesting user's team membership. The docs state that Multi-Team is for organisations that "need resource isolation (Variables, Connections, Secrets, etc) between teams **at the UI and API level**" and that a use case is "You want separate views per team in the Airflow UI" ([Multi-Team → When to Use Multi-Team Mode](https://airflow.apache.org/docs/apache-airflow/stable/core-concepts/multi-team.html#when-to-use-multi-team-mode)). The Work in Progress section lists "Some UI elements may not be fully team-aware" as a known 3.4+ gap. This report concerns the **API** layer — the leak reproduces against the REST endpoints directly, not only through the UI — so it appears to fall outside that caveat. Write operations and Task Execution API access **are** correctly scoped; only list/read appears to be unfiltered. **Setup** Two teams, `team-a` and `team-b`, created via `airflow teams create` and `airflow keycloak-auth-manager create-team`. Per-team Dag bundles: ``` AIRFLOW__DAG_PROCESSOR__DAG_BUNDLE_CONFIG_LIST: [{"name": "team_a_dags", "classpath": "airflow.dag_processing.bundles.local.LocalDagBundle", "kwargs": {"path": "/opt/airflow/dags/team-a"}, "team_name": "team-a"}, {"name": "team_b_dags", "classpath": "airflow.dag_processing.bundles.local.LocalDagBundle", "kwargs": {"path": "/opt/airflow/dags/team-b"}, "team_name": "team-b"}, {"name": "shared_dags", "classpath": "airflow.dag_processing.bundles.local.LocalDagBundle", "kwargs": {"path": "/opt/airflow/dags/shared"}}] ``` `airflow dags list` confirms the association: `dag_id | bundle_name check_dag_running | team_a_dags test_owner_dag | team_b_dags test_dag | shared_dags` `user-a` is a member o…