return list of nodes for lxc driver when called directly
return list of nodes for lxc driver when called directly

This is required so that salt-cloud sees a dictionary list of lxc
containers that exist so that they do not attempt to recreate the
container.

The downside to this is that if the container is stopped, it is not
started.

Fixes #33633

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt