Update Helm release grafana/grafana to v11.6.0

Author: renovate[bot]

examples/prometheus-grafana.yaml

@@ -18,7 +18,7 @@ spec:
   - repositoryURL:    https://grafana-community.github.io/helm-charts
     repositoryName:   grafana
     chartName:        grafana/grafana
-    chartVersion:     11.3.7
+    chartVersion:     11.6.0
     releaseName:      grafana
     releaseNamespace: grafana
     helmChartAction:  Install