Apache Airflow's environment-variable secrets backend resolved a team-scoped Connection or Variable from the wrong team'

Apache Airflow's environment-variable secrets backend resolved a team-scoped Connection or Variable from the wrong team's scope. The guard meant to prevent this only ran when no team scope was supplied, and its pattern could not match a team name containing an underscore, which team names are allowed to contain. When the guard did not apply, the lookup fell through to an unconditional global read that resolved the stored `AIRFLOW_CONN__<TEAM>___<ID>` variable regardless of which team asked. In m