This reverts commit 42f7d3de.

Revert "Revert "Merge branch 'tauhistutils-update-atltau-1368' into '21.0'""

See merge request !5441

This reverts commit c0c84f17.

Revert "Revert "Merge branch '21.0-UpdateRuntTier0Tests-SimTf' into '21.0'""

See merge request !5440

This reverts commit 3fac6ee1.

Revert "Revert "Merge branch '21.0-PyJobTransforms-ATLASJT-370' into '21.0'""

See merge request !5439

This reverts commit ec540e4f.

Revert "Revert "Merge branch '21.0' into '21.0'""

See merge request !5438

This reverts commit e0b3f47d.

Revert 21.0 to r2017-10-05T2151

See merge request !5430

This reverts commit 22969e11, reversing
changes made to f71c4f2b.

This reverts commit 6b05cc73, reversing
changes made to 22969e11.

This reverts commit f1906efb, reversing
changes made to 6b05cc73.

This reverts commit 0389d6a7, reversing
changes made to f1906efb.

This reverts commit d57d58cd, reversing
changes made to 0389d6a7.

This reverts commit c946c5c2, reversing
changes made to d57d58cd.

This reverts commit f1968b3e, reversing
changes made to c946c5c2.

This reverts commit 0752891b, reversing
changes made to f1968b3e.

This reverts commit 66157e9a, reversing
changes made to 0752891b.

This reverts commit 5c17579c, reversing
changes made to 66157e9a.

This reverts commit 58d81c0e, reversing
changes made to 5c17579c.

This reverts commit 8814e168, reversing
changes made to 58d81c0e.

Recovery of the missing Z Tag & Probe plots in the HLT muon offline DQ: ATR-17034

See merge request !5254

Drop Tracking/TrkEvent/TrkTrackLink from AthSimulation

See merge request !5206

Do not output LAr and Tile raw channel containers at premixing

See merge request !5201

LogicalExpressionFilter removed argument for sysExecute

See merge request !5189

Improvements for Long-Lived Particle Vertexing and DAOD_RPVLL Production

See merge request !5173

Overlay ART tests update

See merge request !5172

Add a Sensitive Detector to record FastCaloSim Parametrization inputs

See merge request !5126

Addition of Loose Selection for Release 21.0 for Inner Detector Validation (III)

See merge request !5069

Update to tau physics validation code

See merge request !5062

Implementing Sim_tf.py checks into RunTier0Tests.py

See merge request !4978

Fix: PyJobTransform misses logfile errors containing substep names [ATLASJT-370]

See merge request !4528

Urgent: FastChainPileup RTT test configuration update

See merge request !5130

1) specify outputs to save in tar file
2) print job exit code