This involves two scenarios:

1. Rerun a failed target with a higher priority on the same commit
2. Run a target (which fails in latest run) with a higher priority on a newer commit

For 1), the logic is https://cs.opensource.google/flutter/cocoon/+/main:app_dart/lib/src/service/luci_build_service.dart;l=589, but the rerun is still with the default priority. See the example
Failed task is with priority 30.
The rerun is still with priority 30.

For 2), the logic is
https://cs.opensource.google/flutter/cocoon/+/main:app_dart/lib/src/service/scheduler/policy.dart;l=56, but same issue with 1).

Part of #92300