dagrun.duration.failed metric missing run_type tag when failure caused by dagrun_timeout

[mahirhiro]

Bug

This is a follow-up to #29076, which fixed the missing dagrun.duration.failed
metric emission on dagrun_timeout. That fix added the Stats.timing call to
the timeout path in scheduler_job_runner.py but hardcoded:

tags={"dag_id": dag_run.dag_id}

instead of using dag_run.stats_tags.

The stats_tags property on DagRun (dagrun.py:420) is defined as:

{"dag_id": self.dag_id, "run_type": self.run_type}

The normal finish path (dagrun.py:1648) correctly uses self.stats_tags,
so run_type is present on all non-timeout failures but always absent
from timeout-caused failures.

Impact

It is impossible to filter dagrun.duration.failed by run_type in
monitoring queries when the failure was caused by dagrun_timeout. This
affects monitor accuracy for teams that want to alert only on scheduled
run failures.

Fix

One-line change in task-sdk/src/airflow/jobs/scheduler_job_runner.py
around line 2011:

# Before
tags={"dag_id": dag_run.dag_id}

# After
tags=dag_run.stats_tags

Version

Confirmed present in 3.1.7. Likely affects all versions since #29076
was merged (2.5.2+).

[boring-cyborg]

Thanks for opening your first issue here! Be sure to follow the issue template! If you are willing to raise PR to address this issue please do so, no need to wait for approval.