Update Grafana APT GPG key

roles/monitor/tasks/grafana.yml

 ---
 
+- name: Remove obsolete Grafana APT repository
+  apt_repository:
+    repo: "deb https://packages.grafana.com/oss/deb stable main"
+    state: absent
+
 - name: Install Grafana APT key
-  apt_key:
-    id: 8C8C34C524098CB6
-    url: https://packages.grafana.com/gpg.key
-    state: present
+  copy:
+    src: "grafana.gpg"
+    dest: "/usr/share/keyrings/grafana.gpg"
 
 - name: Install Grafana APT repository
   apt_repository:
-    repo: "deb https://packages.grafana.com/oss/deb stable main"
+    repo: "deb [signed-by=/usr/share/keyrings/grafana.gpg] https://apt.grafana.com stable main"
     state: present
 
 - name: Install Grafana