HepMC2 release, purpose of the build: Hijing fixes Contains MRs: https://gitlab.cern.ch/atlas/athena/-/merge_requests/65493 Hijing: make last changes compile for HepMC2 https://gitlab.cern.ch/atlas/athena/-/merge_requests/65472 Simplifications in the TruthUtils https://gitlab.cern.ch/atlas/athena/-/merge_requests/65470 Add top hadrons to TruthUtils https://gitlab.cern.ch/atlas/athena/-/merge_requests/65476 Further simplifications in the TruthUtils https://gitlab.cern.ch/atlas/athena/-/merge_requests/65434 Add some RHadrons functions to the TruthUtils