Bump Geant4 version to v10.6.3.14
Updates to version with a set of technical patches for:
- ATLASSIM-7244: removal of unneeded logging output from Geant4
- ATLASSIM-7265: support compilation with clang-19
- ATLASSIM-7273: to avoid errors from static destruction in Geant4
No physics changed expected.
MR here requested in ATLASSIM-7265 to make this available on Athena main
first, with a backport(?) to support 24.0
after that. Pinging @jchapman and @mbandier for their info.