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.