Update Helm release k8s-monitoring to v1.6.4

Author: renovate[bot]

disabled/grafana-cloud/Chart.yaml

@@ -3,5 +3,5 @@ name: grafana-cloud
 version: 1.0.0
 dependencies:
 - name: k8s-monitoring
-  version: 1.6.0
+  version: 1.6.4
   repository: https://grafana.github.io/helm-charts