We can start triggering physics and detector pipelines in parallel. We don't need to test physics benchmarks for each test of detector benchmarks, as there is no actual dependency.

This is needed to facilitate running benchmarks where downloads may
happen.

https://github.com/eic/epic/pull/588
fails in
https://eicweb.phy.anl.gov/EIC/benchmarks/detector_benchmarks/-/jobs/2627824

This is similar to https://github.com/eic/physics_benchmarks/pull/5

Resolve "Background benchmark job leads to 12GB download and fills up persistent cache on runner machine"

For this to work, it needs some custom code to create ad-hoc branches with merged PR state. Let's disable this for now.