CHORE(grafana): remove admin login secret for SSO

- Remove grafana-admin-password ExternalSecret
- Remove admin section from helm-values.yaml
- Authentication handled by Authelia SSO middleware

grafana/helm-values.yaml

@@ -15,13 +15,6 @@ affinity:
             app.kubernetes.io/name: grafana
         topologyKey: kubernetes.io/hostname
 
-admin:
-  user: bluemayne
-  # Password is managed via SealedSecret: grafana-admin-password
-  existingSecret: grafana-admin-password
-  userKey: admin-user
-  passwordKey: admin-password
-
 persistence:
   enabled: false