nixos/tests/incus: fix user feature

              server.succeed("incus project show user-1000")

              # users shouldn't be able to list storage pools

              server.fail("su - testuser bash -c 'incus storage list'")

              # user can create an instance

              server.succeed("su - testuser bash -c 'incus create --empty'")

        ''

    + instanceScript;

}