Apache Airflow 2.1.3

### Bug Fixes - Fix task retries when they receive ``sigkill`` and have retries and properly handle ``sigterm`` (#16301) - Fix redacting secrets in context exceptions. (#17618) - Fix race condition with dagrun callbacks (#16741) - Add 'queued' to DagRunState (#16854) - Add 'queued' state to DagRun (#16401) - Fix external elasticsearch logs link (#16357) - Add proper warning message when recorded PID is different from current PID (#17411) - Fix running tasks with ``default_impersonation`` config (#17229) - Rescue if a DagRun's DAG was removed from db (#17544) - Fixed broken json_client (#17529) - Handle and log exceptions raised during task callback (#17347) - Fix CLI ``kubernetes cleanup-pods`` which fails on invalid label key (#17298) - Show serialization exceptions in DAG parsing log (#17277) - Fix: ``TaskInstance`` does not show ``queued_by_job_id`` & ``external_executor_id`` (#17179) - Adds more explanatory message when ``SecretsMasker`` is not configured (#17101) - Enable the use of ``__init_subclass__`` in subclasses of ``BaseOperator`` (#17027) - Fix task instance retrieval in XCom view (#16923) - Validate type of ``priority_weight`` during parsing (#16765) - Correctly handle custom ``deps` and ``task_group`` during DAG Serialization (#16734) - Fix slow (cleared) tasks being be adopted by Celery worker. (#16718) - Fix calculating duration in tree view (#16695) - Fix ``AttributeError``: ``datetime.timezone`` object has no attribute ``name`` (#16599) - Redact conn secrets in webserver logs (#16579) - Change graph focus to top of view instead of center (#16484) - Fail tasks in scheduler when executor reports they failed (#15929) - fix(smart_sensor): Unbound variable errors (#14774) - Add back missing permissions to ``UserModelView`` controls. (#17431) - Better diagnostics and self-healing of docker-compose (#17484) - Improve diagnostics message when users have ``secret_key`` mis-configured (#17410) - Stop checking ``execution_date`` in ``task_instance.refresh_from_db`` (#16809) ### Improvements - Run mini scheduler in ``LocalTaskJob`` during task exit (#16289) - Remove ``SQLAlchemy<1.4`` constraint (#16630) - Bump Jinja2 upper-bound from 2.12.0 to 4.0.0 (#16595) - Bump ``dnspython`` (#16698) - Updates to ``FlaskAppBuilder`` 3.3.2+ (#17208) - Add State types for tasks and DAGs (#15285) - Set Process title for Worker when using ``LocalExecutor`` (#16623) - Move ``DagFileProcessor`` and ``DagFileProcessorProcess`` out of ``scheduler_job.py`` (#16581) ### Doc-only changes - Fix inconsistencies in configuration docs (#17317) - Fix docs link for using SQLite as Metadata DB (#17308) ### Misc - Switch back http provider after requests removes LGPL dependency (#16974)