infra: refact dashboard firewall rules
infra: refact dashboard firewall rules

- There is no need to open ports 3000, 8234, 9283 on all nodes.
- Add missing rule for alertmanager (port 9093)

Closes: #4023

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

ceph/ceph-ansible,ceph/ceph-ansible