Add team_name to Multi-Team metrics

[ferruzzi]

Add team_name to ~35 metrics (DagRun, TaskInstance, pool slots) for multi-team Airflow deployments. When multi_team is disabled or a DAG has no team, the tag is omitted entirely (no change to existing systems).

Changes:

• Add team_name to DagRun.stats_tags and TaskInstance.stats_tags
• Set _team_name on DagRun/TI objects in 4 scheduler injection points
• Add persistent _dag_id_to_team_name cache on SchedulerJobRunner
• Add stats_tags property to RuntimeTaskInstance (Task SDK)
• Add team_name to pool slot gauge metrics via pool.get_name_to_team_name_mapping

Remaining metrics will be done in (6 or 7?) parallel chunks after this lands.

Co-authored-by: Niko Oliveira onikolas@amazon.com

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