CI: add MR build job for mCBM tests using realData runner
Add a new build job on each MR doing:
- Build under Debian 10
- Testing including the real data analysis from beamtimes/test setups (for now only mCBM)
The job is set to 16 cores which could allow having up to 3 concurrent jobs (56 cores on this node), but no garantie for the HDD perfs.
All user forks listed for CbmRoot_macosx (demac006) and CbmRoot (lxir116) were also added to the new runner CbmRoot_realData (run4.cbm.gsi.de), so it should be transparent for them.