Merge 21.0.110 into 21.3

This merge request merges all the changes that were made to the 21.0 branch between the release release/21.0.110 and the previous release release/21.0.109.

Below is the full list of merge requests that were included between these two tags:

• !31125 (merged) : Adding ART tests for testing Tracking overlay
• !30863 (merged) : Change BCID structure to trees
• !30900 (merged) : Fix nhit calculation and debug output in TFCSLateralShapeParametrizationHitChain
• !30922 (merged) : Update TrackEventAthenaPool unit test reference files after changes in !28312 (merged).

Link to the full diff between release/21.0.110 and release/21.0.109 is available at https://gitlab.cern.ch/atlas/athena/compare/release/21.0.109...release/21.0.110

added sweep:from 21.0 sweep:ignore labels

This merge request affects 4 packages:

• DataQuality/DataQualityTools
• Simulation/FastSimulation/FastChainPileup
• Simulation/ISF/ISF_FastCaloSim/ISF_FastCaloSimEvent
• Tracking/TrkEventCnv/TrkEventAthenaPool

Adding @jchapman ,@amorley ,@pjacka ,@mfauccig ,@xiaozhon ,@ahasib ,@vpascuzz ,@tadej ,@schaarsc as watchers

added 21.3 DQ Simulation Tracking review-pending-level-1 labels

CI Result SUCCESS (hash 9ee521d4)

	Athena
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST 43176]

This is basically a sweep of already-reviewed changes, and the CI looks good: this is OK to go.

MLB (L1)

added review-approved label and removed review-pending-level-1 label

mentioned in commit d46c0fd4

merged

mentioned in merge request !31887 (merged)

mentioned in commit a2a70552