geant4: repoint default data dir to EOS
This updates the FindGeant4
module to use EOS rather than AFS as the default location for Geant4's data libraries. An EOS area has been populated with the same directory structure as the AFS area, and a file-by-file hash comparison done to confirm contents are identical. See ATLASSIM-3175 for further details.
As noted in that ticket, this change should only target master
branches here and in Athena. It can be back ported for Athena 22.0, depending on which branch to target. But we should confirm changes are o.k. here first! A similar MR will be needed in atlas-sit/librarian-rpm.