chore(deps): update kube-prometheus-stack docker tag to v81.6.0 (#3873)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [kube-prometheus-stack](https://github.com/prometheus-operator/kube-prometheus) ([source](https://github.com/prometheus-community/helm-charts)) | minor | `81.5.2` → `81.6.0` |

---

### Release Notes

<details>
<summary>prometheus-community/helm-charts (kube-prometheus-stack)</summary>

### [`v81.6.0`](https://github.com/prometheus-community/helm-charts/releases/tag/kube-prometheus-stack-81.6.0)

[Compare Source](https://github.com/prometheus-community/helm-charts/compare/kube-prometheus-stack-81.5.2...kube-prometheus-stack-81.6.0)

kube-prometheus-stack collects Kubernetes manifests, Grafana dashboards, and Prometheus rules combined with documentation and scripts to provide easy to operate end-to-end Kubernetes cluster monitoring with Prometheus using the Prometheus Operator.

#### What's Changed

- \[CI] Update dependency helm/helm to v4.1.1 by [@&#8203;renovate](https://github.com/renovate)\[bot] in [#&#8203;6627](https://github.com/prometheus-community/helm-charts/pull/6627)
- \[kube-prometheus-stack] Update kube-prometheus-stack dependency non-major updates by [@&#8203;renovate](https://github.com/renovate)\[bot] in [#&#8203;6628](https://github.com/prometheus-community/helm-charts/pull/6628)

**Full Changelog**: <https://github.com/prometheus-community/helm-charts/compare/kube-prometheus-stack-81.5.2...kube-prometheus-stack-81.6.0>

</details>

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---

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---

This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
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Reviewed-on: #3873
Co-authored-by: Renovate Bot <renovate-bot@alexlebens.net>
Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

clusters/cl01tl/helm/kube-prometheus-stack/Chart.lock

@@ -1,12 +1,12 @@
 dependencies:
 - name: kube-prometheus-stack
   repository: oci://ghcr.io/prometheus-community/charts
-  version: 81.5.2
+  version: 81.6.0
 - name: app-template
   repository: https://bjw-s-labs.github.io/helm-charts/
   version: 4.6.2
 - name: redis-replication
   repository: oci://harbor.alexlebens.net/helm-charts
   version: 1.0.4
-digest: sha256:1d78f3bccfa85f72b67f98b2a39946e7e8a3fa3cc9a23f85c843ac3bba191a12
-generated: "2026-02-09T22:58:10.325511368Z"
+digest: sha256:c72007e1f7faf89fddc4058d2e038ae74fdbf0a49ac50063f67a78447fe3d84c
+generated: "2026-02-10T02:01:54.512608335Z"