This might be a niche use case, but our alerting system requires all alerts to retain a specific label used to associate alerts with configuration items. We've addressed the most common violations using the promql/aggregate check, which ensures labels are not dropped during aggregation. However, we also need a mechanism to enforce label matchers in alerts that use the absent() function.

Specifically, we propose a new check that flags expressions like absent(metric) or absent(metric{}) where no label matchers are provided. The check should function analogously to promql/aggregate, validating that absent() is scoped with appropriate label constraints.