Improve handling of TARGETVOLUME in VolumeDebugger
Skip running VolumeDebugger
if $TARGETVOLUME
is set to NONE
.
This will save time and avoid Warning messages for changes that don't affect the geometry (e.g. README updates, etc) in the ITKLayouts
CI Tests:
https://gitlab.cern.ch/Atlas-Inner-Tracking/ITKLayouts/-/merge_requests/75