ATLASSIM-4948: Bump Geant4/CLHEP versions to v10.6.3.2/v2.4.1.3

This implements the version bump to Geant4 10.6.3 + ATLAS patches requested in ATLASSIM-4948. This includes a version bump of CLHEP from CLHEP_2_4_0_1_atl02 to CLHEP_2_4_1_3 to match the version recommended by Geant4 for 10.6.3. No ATLAS patches appear needed for this CLHEP version, it includes those added in the atl02 patch to CLHEP_2_4_0_1_atl02.

No changes other than updating the tags were needed in atlasexternals. I've marked as WIP as the data libraries for 10.6.3 are on AFS, but require publication and the creation of the RPMs. If that should be done before testing/merging this MR, let me know and I'll raise the relevant ATLINFR ticket.