Draft: Port fix needed for running from nighlty and release build in LHCb when using G4 10.7

LHCbPR tests do not run because it looks for PTL at run time in the LHCb external even though it is only needed internally by Geant4 that has its own copy.

It may be closed without merging if protection is deployed in time

cc: @dpopov, @mimazure, @clemenci