Add controller.metrics.serviceMonitor.annotations in Helm chart (#9677)

Signed-off-by: Mathieu Parent <math.parent@gmail.com>

charts/ingress-nginx/values.yaml

@@ -867,6 +867,7 @@ controller:
     serviceMonitor:
       enabled: false
       additionalLabels: {}
+      annotations: {}
       ## The label to use to retrieve the job name from.
       ## jobLabel: "app.kubernetes.io/name"
       namespace: ""