add comment on non gpu and non openmp variants

toolchains/foss2021a-cuda-mpi/spack.yaml

@@ -32,8 +32,8 @@ spack:
     - netcdf-fortran@4.6.0 ^netcdf-c+mpi
     - etsf-io@1.0.4
     - bigdft-futile@1.9.2+mpi
-    - bigdft-psolver@1.9.2+mpi~cuda
-    - dftbplus@21.2~arpack~dftd3~elsi~gpu~mpi~sockets~transport+api+sharedlibs~openmp
+    - bigdft-psolver@1.9.2+mpi~cuda  # octopus does not use cuda variant
+    - dftbplus@21.2~arpack~dftd3~elsi~gpu~mpi~sockets~transport+api+sharedlibs~openmp  # non gpu and non openmp variant based on the easybuild configuration (octopus does not use gpu variant)
     # - openblas@0.3.15
     # - libpspio@0.2.4  # missing in spack
   specs:

toolchains/foss2022a-cuda-mpi/spack.yaml

@@ -32,8 +32,8 @@ spack:
     - netcdf-fortran@4.6.0 ^netcdf-c+mpi
     - etsf-io@1.0.4
     - bigdft-futile@1.9.2+mpi
-    - bigdft-psolver@1.9.2+mpi~cuda
-    - dftbplus@21.2~arpack~dftd3~elsi~gpu~mpi~sockets~transport+api+sharedlibs~openmp
+    - bigdft-psolver@1.9.2+mpi~cuda  # octopus does not use cuda variant
+    - dftbplus@21.2~arpack~dftd3~elsi~gpu~mpi~sockets~transport+api+sharedlibs~openmp # non gpu and non openmp variant based on the easybuild configuration (octopus does not use gpu variant)
     # - openblas@0.3.15
     # - libpspio@0.2.4  # missing in spack
   specs: