Switch Ubuntu CI from tcl to lmod

.github/workflows/ubuntu-ci-x86_64.yaml

@@ -123,6 +123,9 @@ jobs:
           spack config add "packages:all:compiler:[[email protected]]"
           sed -i "s/\['\%aocc', '\%apple-clang', '\%gcc', '\%intel'\]/\['\%intel'\]/g" $ENVDIR/spack.yaml
 
+          # Switch from default tcl to lmod modules
+          sed -i "s/tcl/lmod/g"'" $ENVDIR/site/modules.yaml
+
           spack concretize 2>&1 | tee log.concretize.intel-2022.1.0
           ${SPACK_STACK_DIR}/util/show_duplicate_packages.py -d log.concretize.intel-2022.1.0 -i fms -i crtm
 
@@ -159,7 +162,7 @@ jobs:
           # Next steps: synchronize source and build cache to a central/combined mirror?
           echo "Next steps ..."
           spack clean -a
-          spack module tcl refresh -y
+          spack module lmod refresh -y
           spack stack setup-meta-modules
           spack env deactivate