Revert "Raise spack to 0.23.1"

This reverts commit c290fc6.

Author: franzpoeschel

.github/workflows/dependencies/install_spack

@@ -3,7 +3,7 @@
 
 set -eu -o pipefail
 
-spack_ver="0.23.1"
+spack_ver="0.22.3"
 
 cd /opt
 if [[ -d spack && ! -f spack_${spack_ver} ]]