Switch from +dd4hep to +detdesc in lhcb-head-2
We agreed at the latest Core Software Meeting to switch, as of LCG 102, the default platforms to enable DD4hep and replace the special platforms +dd4hep
with +detdesc
equivalent ones for testing.
This MR changes the list of platforms in lhcb-head-2
replacing +dd4hep
with +detdesc
(there's a bit of refactoring the make it easier).
This cannot be merged until lcg-toolchains!114 (merged) is merged and deployed, and makes sense only if lhcb/LHCb!3903 (merged) is labeled to be included in lhcb-head-2
.