chore(deps): update docker/build-push-action action to v7 (#177)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [docker/build-push-action](https://github.com/docker/build-push-action) | action | major | `v6` → `v7` |

---

### Release Notes

<details>
<summary>docker/build-push-action (docker/build-push-action)</summary>

### [`v7`](https://github.com/docker/build-push-action/compare/v6...v7)

[Compare Source](https://github.com/docker/build-push-action/compare/v6...v7)

</details>

---

### 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

---

This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
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Reviewed-on: #177
Co-authored-by: Renovate Bot <renovate-bot@alexlebens.net>
Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

.gitea/workflows/release-image-gitea.yml

@@ -94,7 +94,7 @@ jobs:
           fi
 
       - name: Build and Push Image
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: .
           push: true

.gitea/workflows/release-image-harbor.yml

@@ -94,7 +94,7 @@ jobs:
           fi
 
       - name: Build and Push Image
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@v7
         with:
           context: .
           push: true