Update dependency grafana to v11.6.4-0

requirements.yml

@@ -22,7 +22,7 @@
   version: v4.98.1-r0-2-0
   name: exim_relay
 - src: git+https://github.com/mother-of-all-self-hosting/ansible-role-grafana.git
-  version: v11.6.3-1
+  version: v11.6.4-0
   name: grafana
 - src: git+https://github.com/mother-of-all-self-hosting/ansible-role-jitsi.git
   version: v10314-1