Update Helm release gatus to v1.4.0 (#1394)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [gatus](https://github.com/TwiN/gatus) ([source](https://github.com/TwiN/helm-charts)) | minor | `1.3.1` -> `1.4.0` |

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### Release Notes

<details>
<summary>TwiN/helm-charts (gatus)</summary>

### [`v1.4.0`](https://github.com/TwiN/helm-charts/releases/tag/gatus-1.4.0)

[Compare Source](https://github.com/TwiN/helm-charts/compare/gatus-1.3.1...gatus-1.4.0)

Automated service health dashboard

</details>

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### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

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This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
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Reviewed-on: #1394
Co-authored-by: Renovate Bot <renovate-bot@alexlebens.net>
Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

clusters/cl01tl/monitoring/gatus/Chart.yaml

@@ -19,7 +19,7 @@ maintainers:
 dependencies:
   - name: gatus
     repository: https://twin.github.io/helm-charts
-    version: 1.3.1
+    version: 1.4.0
   - name: postgres-cluster
     alias: postgres-17-cluster
     version: 5.1.0