Use the correct option for mount only

Author: ocaisa

.github/workflows/minimal-usage.yml

@@ -39,6 +39,9 @@ jobs:
     steps:
     - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - uses: ./
+      with:
+        mount_cvmfs_only: 'true'
+        init_direnv: 'false'
     - name: Test EESSI not initialised
       run: |
         if [[ -v EESSI_VERSION ]]; then