chore(deps): update xenrox/ntfy-alertmanager docker tag to v1 (#5312)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| xenrox/ntfy-alertmanager | major | `0.5.0` → `1.0.0` |

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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.

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

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Reviewed-on: #5312
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Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

clusters/cl01tl/helm/kube-prometheus-stack/values.yaml

@@ -148,7 +148,7 @@ ntfy-alertmanager:
         main:
           image:
             repository: xenrox/ntfy-alertmanager
-            tag: 0.5.0
+            tag: 1.0.0
             pullPolicy: IfNotPresent
   service:
     main: