Removing old sensitive detector package for HGTD

Removing currently completely unused old HGTDG4SD package under LAr, in favor of new code which will go into HGTD_ReadoutGeometry, towards https://its.cern.ch/jira/browse/ATLSWUPGR-92. As discussed with @jchapman earlier.

Tagging @dshope and @aleopold for info.

Best, Christian

This merge request affects 1 package:

• LArCalorimeter/LArG4/HGTDG4SD

Adding @pavol as watcher

added 21.9 JetEtmiss LAr Simulation review-pending-level-1 labels

CI Result SUCCESS (hash 2c6d71d0)

	Athena
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 156
For experts only: Jenkins output [CI-MERGE-REQUEST 44556]

The changes are trivial, approving. Cheers, Hasib (L1)

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

merged

mentioned in commit 724b3269

added sweep:ignore label

mentioned in merge request !38312 (merged)