Add special label that exludes this always full PVC from the Alert Ku…

…bePersistentVolumeFillingUp

The volume is meant to be full so the standard monitoring alert will be noise.

The alert is described at https://github.com/prometheus-operator/kube-prometheus/wiki/kubepersistentvolumefillingup

But I found a magic label that can be attached to the PVC:

kubernetes-monitoring/kubernetes-mixin#711

production/helm/loki/templates/memcached/_memcached-statefulset.tpl

@@ -163,6 +163,8 @@ spec:
   volumeClaimTemplates:
     - metadata:
         name: data
+        labels:
+          excluded_from_alerts: "true"
       spec:
         accessModes: [ "ReadWriteOnce" ]
         {{- with .persistence.storageClass }}