Update https://gitea.seeseepuff.be/actions/watchtower action to v2 (#9)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [https://gitea.seeseepuff.be/actions/watchtower](https://gitea.seeseepuff.be/actions/watchtower) | action | major | `v1` → `v2` |

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### Release Notes

<details>
<summary>actions/watchtower (https://gitea.seeseepuff.be/actions/watchtower)</summary>

### [`v2`](https://gitea.seeseepuff.be/actions/watchtower/compare/v1...v2)

[Compare Source](https://gitea.seeseepuff.be/actions/watchtower/compare/v1...v2)

</details>

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Reviewed-on: #9
Co-authored-by: Renovate Bot <sebastiaan.de.schaetzen+renovate@gmail.com>
Co-committed-by: Renovate Bot <sebastiaan.de.schaetzen+renovate@gmail.com>

.gitea/workflows/deploy.yml

@@ -35,4 +35,4 @@ jobs:
         run: docker push gitea.seeseepuff.be/seeseemelk/webgit:latest
 
       - name: Trigger Watchtower
-        uses: https://gitea.seeseepuff.be/actions/watchtower@3c31a0da833fadae874b66f14d5f61980dc4f07b # v1
+        uses: https://gitea.seeseepuff.be/actions/watchtower@2bf31c49a6f57d45a1580c7004911afb714fb188 # v2

build.gradle.kts

@@ -1,7 +1,7 @@
 plugins {
     java
     jacoco
-    id("org.springframework.boot") version "4.0.3"
+    id("org.springframework.boot") version "4.0.6"
     id("io.spring.dependency-management") version "1.1.7"
 }