Manage guix evolution for stability of Proxy's TPL and Proxy

Recent changement on Guix (Guix channel and Guix HPC) broke the stability of our package definition (for example the remove of the old kokkos version). Solutions should be explored to be less dependant of Guix evolution. It could be to reduce considerably the dependance on Guix channel (involving duplicating code) or using time_machine options (leading to slow-down).