fix(helm): update k8s-monitoring ( 1.6.19 → 1.6.21 ) (#6209)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [k8s-monitoring](https://redirect.github.com/grafana/helm-charts) |
patch | `1.6.19` -> `1.6.21` |

---

### Release Notes

<details>
<summary>grafana/helm-charts (k8s-monitoring)</summary>

###
[`v1.6.21`](https://redirect.github.com/grafana/helm-charts/releases/tag/k8s-monitoring-1.6.21)

[Compare
Source](https://redirect.github.com/grafana/helm-charts/compare/k8s-monitoring-1.6.19...k8s-monitoring-1.6.21)

A Helm chart for gathering, scraping, and forwarding Kubernetes
telemetry data to a Grafana Stack.

Source commit:
grafana/k8s-monitoring-helm@e8c368a

Tag on source:
https://github.com/grafana/k8s-monitoring-helm/releases/tag/v1.6.21

</details>

---

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are satisfied.

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---

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---

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kubernetes/kyak/apps/monitoring/grafana-k8s-monitoring/app/helmrelease.yaml

@@ -9,7 +9,7 @@ spec:
   chart:
     spec:
       chart: k8s-monitoring
-      version: 1.6.19
+      version: 1.6.21
       sourceRef:
         kind: HelmRepository
         name: grafana