Switch to using the `CLHEP_2_2_0_4_atl10` from the ATLAS fork of CLHEP.
CLHEP_2_2_0_4_atl10
corresponds to the official CLHEP_2_2_0_4
tag plus the gcc8 compilation
fixes from External/CLHEP/patches/overridden-virtual-warning.patch
.
atlas-sw-git/CLHEP@CLHEP_2_2_0_4...CLHEP_2_2_0_4_atl10
Should fix ATLINFR-2735.