More standard way to find libclang
The original lookup was taking 20s (it tried a matrix of versions). It failed, and we fell back to using the /cvmfs/sft.cern.ch install, which is not ideal.
This only works together with lhcb-core/lcg-toolchains!80 which adds clang to the CMAKE_PREFIX_PATH
Edited by Daniel Hugo Campora Perez