unbound(role): use existing deploy_systemd_resolved_config role and some reordering

roles/unbound/tasks/prometheus-exporter.yml

@@ -3,7 +3,13 @@
   become: true
   ansible.builtin.package:
     name: prometheus-unbound-exporter
-  notify: prometheus-unbound-exporter.enabled
+
+- name: enable unbound prometheus exporter
+  become: true
+  ansible.builtin.systemd:
+    name: prometheus-unbound-exporter.service
+    enabled: true
+    daemon_reload: true
 
 - name: configure unbound exporter
   become: true