Airflow - 2.6.3

Bug Fixes

• Use linear time regular expressions (#32303)
• Fix triggerers alive check and add a new conf for triggerer heartbeat rate (#32123)
• Catch the exception that triggerer initialization failed (#31999)
• Hide sensitive values from extra in connection edit form (#32309)
• Sanitize DagRun.run_id and allow flexibility (#32293)
• Add triggerer canceled log (#31757)
• Fix try number shown in the task view (#32361)
• Retry transactions on occasional deadlocks for rendered fields (#32341)
• Fix behaviour of LazyDictWithCache when import fails (#32248)
• Remove executor_class from Job - fixing backfill for custom executors (#32219)
• Fix bugged singleton implementation (#32218)
• Use mapIndex to display extra links per mapped task. (#32154)
• Ensure that main triggerer thread exits if the async thread fails (#32092)
• Use re2 for matching untrusted regex (#32060)
• Render list items in rendered fields view (#32042)
• Fix hashing of dag_dependencies in serialized dag (#32037)
• Return None if an XComArg fails to resolve in a multiple_outputs Task (#32027)
• Check for DAG ID in query param from url as well as kwargs (#32014)
• Flash an error message instead of failure in rendered-templates when map index is not found (#32011)
• Fix ExternalTaskSensor when there is no task group TIs for the current execution date (#32009)
• Fix number param html type in trigger template (#31980, #31946)
• Fix masking nested variable fields (#31964)
• Fix operator_extra_links property serialization in mapped tasks (#31904)
• Decode old-style nested Xcom value (#31866)
• Add a check for trailing slash in webserver base_url (#31833)
• Fix connection uri parsing when the host includes a scheme (#31465)
• Fix database session closing with xcom_pull and inlets (#31128)
• Fix DAG's on_failure_callback is not invoked when task failed during testing dag. (#30965)
• Fix airflow module version check when using ExternalPythonOperator and debug logging level (#30367)

Misc/Internal

• Fix task.sensor annotation in type stub (#31954)
• Limit Pydantic to < 2.0.0 until we solve 2.0.0 incompatibilities (#32312)
• Fix Pydantic 2 pickiness about model definition (#32307)

Doc only changes

• Add explanation about tag creation and cleanup (#32406)
• Minor updates to docs (#32369, #32315, #32310, #31794)
• Clarify Listener API behavior (#32269)
• Add information for users who ask for requirements (#32262)
• Add links to DAGRun / DAG / Task in Templates Reference (#32245)
• Add comment to warn off a potential wrong fix (#32230)
• Add a note that we'll need to restart triggerer to reflect any trigger change (#32140)
• Adding missing hyperlink to the tutorial documentation (#32105)
• Added difference between Deferrable and Non-Deferrable Operators (#31840)
• Add comments explaining need for special "trigger end" log message (#31812)
• Documentation update on Plugin updates. (#31781)
• Fix SemVer link in security documentation (#32320)
• Update security model of Airflow (#32098)
• Update references to restructured documentation from Airflow core (#32282)
• Separate out advanced logging configuration (#32131)
• Add ™ to Airflow in prominent places (#31977)