Merge 21.0.96 into 21.3 branch

This merge request merges the changes which went into the 21.0 branch between the release/21.0.95 and release/21.0.96 tags into the 21.3 branch.

This is the list of merge requests that were included since the previous release release/21.0.95:

• !22856 (merged) : PixelGeoModel: comment unused flexDensity variable to avoid compiler warning
• !22860 (merged) : fixed some warnings in PixelRadDamDigitization
• !22260 (merged) : Updates to R-Hadron simulation for stable particles
• !22778 (merged) : Sweeping !22721 (merged) from 21.3 to 21.0.
• !22833 (merged) : RadiationMapsMaker: energy spectra
• !22715 (merged) : Cherry-pick fixes in trigger test exec scripts
• !22691 (merged) : Add new G4FastCaloTest simulator configuration
• !22558 (merged) : Update for 2018 PbPb overlay configuration
• !22659 (merged) : Sweeping !22586 (merged) from 21.3 to 21.0.
• !22579 (merged) : Sweeping !22537 (merged) from 21.3 to 21.0.
• !21530 (merged) : Fix LArG4Identifier assignment for hits from step in Back Outer Barrette
• !22077 (merged) : Added photon Russian Roulette
• !22123 (merged) : better memory management in Geo2G4Svc
• !22129 (merged) : minor fixes TileCalibBlobPython package
• !22305 (merged) : 21.0-ART_test-InDetPhysValMonitoring
• !22379 (merged) : Sweeping !22165 (merged) from master to 21.0.
• !22495 (merged) : Removing MadGraphModels package from 21.0
• !22514 (merged) : Use InDetSCT_ConditionsSummarySvc, use groupSize in SCTRationNoiseMonTool (ATLASRECTS-4839)
• !22315 (merged) : 21.0 fcs debugging histograms
• !22337 (merged) : Fixing unused variable warning reported in ATLASSIM-4125
• !22161 (merged) : For Forward-Compatibility port reading of RootTreeIndexContainer
• !22193 (merged) : Improving tracking for High Pt B hadrons
• !22230 (merged) : Fix configuration issues with ATLFASTII_QS simulator
• !22182 (merged) : test_MC16_ATLFASTIIF_ttbar ART job should run on grid not as part of ART build
• !22167 (merged) : improved Geantino weighting for density averaging in RadiationMapsMaker
• !22146 (merged) : Update to RHadron Mass Spectrum for Spin Issue
• !22111 (merged) : adds logical volume printout as well
• !22053 (merged) : Extend ISF configuration to allow Quasi-stable particle simulation in ATLFASTII jobs
• !21766 (merged) : Egamma ART: Adding cluster plots and modifying plotting macro
• !21943 (merged) : Sweeping !21781 (merged) from 21.2 to 21.0.
• !21959 (merged) : Sweeping !21757 (merged) from 21.3 to 21.0.
• !22032 (merged) : 21.0 RHadron consistency
• !22035 (merged) : Sweeping !21996 (merged) from master to 21.0.
• !22054 (merged) : timeout variables in h2000 TileCal calibration ntuple
• !22078 (merged) : Add MC16 Simulation ART jobs
• !22081 (merged) : Switch off FastChainPileup ART jobs for 21.0 branch

Link to the full diff between release/21.0.96 and release/21.0.95 is available at https://gitlab.cern.ch/atlas/athena/compare/release/21.0.95...release/21.0.96