Update build.yml with required parameters.

conf/common/build.yml

 spack:
-  url: git@gitlab.physik.uni-muenchen.de:LDAP_rbg/spack.git
-  branch: lmu/ubuntu20.04-icon
-  compiler: gcc@11.3.0
+  #url: git@gitlab.physik.uni-muenchen.de:LDAP_rbg/spack.git
+  #branch: lmu/ubuntu20.04-icon
+  #compiler: gcc@11.3.0
+  init: "" # command to load spack environment, e.g. module load spack, use spack/setup-env.sh if empty
+  url: https://github.com/spack/spack.git # url to download spack if necessary
+  branch: develop # if downloaded, branch name to use
+  compiler: gcc@12.2.0 # desired compiler for spack
+  root: "%HPCROOTDIR%/spack" # path to a spack install, will be downloaded to if not present
+  user_cache_path: "%HPCROOTDIR%/spack_user_cache_path" # spack puts data here when bootstrapping, leave empty to use home folder
+  disable_local_config: true # if false, spack install into home folder
+  build_cmd: "icon-nwp@%icon.version% ^openmpi+pmi+legacylaunchers schedulers=slurm fabrics=ucx ucx+dc+dm+ib_hw_tm+mlx5_dv+rc+rdmacm+thread_multiple+ud+verbs ^gettext@0.20.2 ^%spack.compiler%"
 
 python_environment:
   # Name of the virtual environment in the remote platform experiment folder