gvisor: molecule: move variables to inventory

Fix download/file (which needs the variable to determine the correct
binaries)

roles/container-engine/gvisor/molecule/default/molecule.yml

@@ -21,6 +21,11 @@ provisioner:
     defaults:
       callbacks_enabled: profile_tasks
       timeout: 120
+  inventory:
+    group_vars:
+      k8s_cluster:
+        gvisor_enabled: true
+        container_manager: containerd
   playbooks:
     create: ../../../../../tests/cloud_playbooks/create-kubevirt.yml
     prepare: ../../../molecule/prepare.yml