re-init tofu after changing branches

Author: sjpb

.github/workflows/stackhpc.yml

@@ -197,6 +197,7 @@ jobs:
           . environments/.stackhpc/activate
           cp $STACKHPC_TF_DIR_OLD/terraform.tfstate $STACKHPC_TF_DIR_NEW
           cd $STACKHPC_TF_DIR_NEW
+          tofu init
           tofu apply -auto-approve -var-file="${{ env.CI_CLOUD }}.tfvars"
           
       - name: Configure cluster using current branch