chore(deps): update docker/build-push-action action to v7 (#101)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [docker/build-push-action](https://github.com/docker/build-push-action) | action | major | `v6.19.2` → `v7.0.0` |

---

### Release Notes

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

### [`v7.0.0`](https://github.com/docker/build-push-action/releases/tag/v7.0.0)

[Compare Source](https://github.com/docker/build-push-action/compare/v6.19.2...v7.0.0)

- Node 24 as default runtime (requires [Actions Runner v2.327.1](https://github.com/actions/runner/releases/tag/v2.327.1) or later) by [@&#8203;crazy-max](https://github.com/crazy-max) in [#&#8203;1470](https://github.com/docker/build-push-action/pull/1470)
- Remove deprecated `DOCKER_BUILD_NO_SUMMARY` and `DOCKER_BUILD_EXPORT_RETENTION_DAYS` envs by [@&#8203;crazy-max](https://github.com/crazy-max) in [#&#8203;1473](https://github.com/docker/build-push-action/pull/1473)
- Remove legacy export-build tool support for build summary by [@&#8203;crazy-max](https://github.com/crazy-max) in [#&#8203;1474](https://github.com/docker/build-push-action/pull/1474)
- Switch to ESM and update config/test wiring by [@&#8203;crazy-max](https://github.com/crazy-max) in [#&#8203;1466](https://github.com/docker/build-push-action/pull/1466)
- Bump [@&#8203;actions/core](https://github.com/actions/core) from 1.11.1 to 3.0.0 in [#&#8203;1454](https://github.com/docker/build-push-action/pull/1454)
- Bump [@&#8203;docker/actions-toolkit](https://github.com/docker/actions-toolkit) from 0.62.1 to 0.79.0 in [#&#8203;1453](https://github.com/docker/build-push-action/pull/1453) [#&#8203;1472](https://github.com/docker/build-push-action/pull/1472) [#&#8203;1479](https://github.com/docker/build-push-action/pull/1479)
- Bump minimatch from 3.1.2 to 3.1.5 in [#&#8203;1463](https://github.com/docker/build-push-action/pull/1463)

**Full Changelog**: <https://github.com/docker/build-push-action/compare/v6.19.2...v7.0.0>

</details>

---

### Configuration

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

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

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---

 - [ ] <!-- 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: #101
Reviewed-by: t.behrendt <t.behrendt@noreply.localhost>
Co-authored-by: Renovate Bot <renovate@t00n.de>
Co-committed-by: Renovate Bot <renovate@t00n.de>

.gitea/workflows/cd.yaml

@@ -68,7 +68,7 @@ jobs:
           echo REPO_VERSION=$(git describe --tags --always | sed 's/^v//') >> $GITHUB_OUTPUT
 
       - name: Build and push
-        uses: docker/build-push-action@10e90e3645eae34f1e60eeb005ba3a3d33f178e8 # v6.19.2
+        uses: docker/build-push-action@d08e5c354a6adb9ed34480a06d141179aa583294 # v7.0.0
         with:
           context: .
           file: ./Dockerfile