Update ghcr.io/twin/gatus Docker tag to v5.31.0 (#2008)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [ghcr.io/twin/gatus](https://github.com/TwiN/gatus) | minor | `v5.30.0` -> `v5.31.0` |

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### Release Notes

<details>
<summary>TwiN/gatus (ghcr.io/twin/gatus)</summary>

### [`v5.31.0`](https://github.com/TwiN/gatus/releases/tag/v5.31.0)

[Compare Source](https://github.com/TwiN/gatus/compare/v5.30.0...v5.31.0)

Highlight of this release are the ability to mark announcements as "archived", which renders said announcements in a new `Past Announcements` section at the bottom of the status page (only rendered if there is at least 1 archived announcements), support for markdown in announcements and support for monitoring gRPC health endpoints.

<img width="1166" height="556" alt="image" src="https://github.com/user-attachments/assets/d22a0ea7-c035-4c35-a148-6de097a357b7" />

#### What's Changed
* feat(announcements): Add support for archived announcements and add past announcement section in UI by @&#8203;TwiN in https://github.com/TwiN/gatus/pull/1382
* feat(announcements): add markdown support by @&#8203;Sworyz in https://github.com/TwiN/gatus/pull/1371
* feat(client): Add support for monitoring gRPC endpoints by @&#8203;diamanat in https://github.com/TwiN/gatus/pull/1376
* fix(client): update icmp/ping logic to determine pinger privileged mode by @&#8203;h3mmy in https://github.com/TwiN/gatus/pull/1346
* fix(api): Escape endpoint key in URL for raw APIs by @&#8203;Nedra1998 in https://github.com/TwiN/gatus/pull/1381
* docs(readme): adds ECS fargate module in README by @&#8203;GiamPy5 in https://github.com/TwiN/gatus/pull/1377

#### New Contributors
* @&#8203;GiamPy5 made their first contribution in https://github.com/TwiN/gatus/pull/1377
* @&#8203;h3mmy made their first contribution in https://github.com/TwiN/gatus/pull/1346
* @&#8203;diamanat made their first contribution in https://github.com/TwiN/gatus/pull/1376
* @&#8203;Nedra1998 made their first contribution in https://github.com/TwiN/gatus/pull/1381
* @&#8203;Sworyz made their first contribution in https://github.com/TwiN/gatus/pull/1371

**Full Changelog**: <https://github.com/TwiN/gatus/compare/v5.30.0...v5.31.0>

</details>

---

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---

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---

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Reviewed-on: #2008
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clusters/cl01tl/monitoring/gatus/values.yaml

@@ -7,7 +7,7 @@ gatus:
     enabled: true
   image:
     repository: ghcr.io/twin/gatus
-    tag: v5.30.0
+    tag: v5.31.0
   annotations:
     reloader.stakater.com/auto: "true"
   service: