dashboard: do not deploy on Debian based OS/non-containerized
dashboard: do not deploy on Debian based OS/non-containerized

in non-containerized deployment, we can't deploy dashboard on Debian
based distribution since the package `ceph-grafana-dashboards` isn't
available.

Signed-off-by: Guillaume Abrioux <30a9df5a0293a6108675377fa1673f7aa713f915@redhat.com>

ceph/ceph-ansible,ceph/ceph-ansible