chore(deps): update woodpeckerci/plugin-docker-buildx docker tag to v3.1.0 (#23)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [woodpeckerci/plugin-docker-buildx](https://codeberg.org/woodpecker-plugins/docker-buildx) ([source](https://codeberg.org/woodpecker-plugins/docker-buildx.git)) | minor | `3.0.1` -> `3.1.0` |

---

### Release Notes

<details>
<summary>woodpecker-plugins/docker-buildx (woodpeckerci/plugin-docker-buildx)</summary>

### [`v3.1.0`](https://codeberg.org/woodpecker-plugins/docker-buildx/releases/tag/v3.1.0)

[Compare Source](https://codeberg.org/woodpecker-plugins/docker-buildx/compare/v3.0.1...v3.1.0)

#### Features

-   Improve support for `cache_to` and `cache_from` & add `cache_images` ([#&#8203;129](https://github.com/woodpecker-plugins/docker-buildx/issues/129))

#### Dependencies

-   chore(deps): update docker docker tag to v25.0.2

</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).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy4xNzUuMCIsInVwZGF0ZWRJblZlciI6IjM3LjE3NS4wIiwidGFyZ2V0QnJhbmNoIjoibWFpbiJ9-->

Reviewed-on: #23
Co-authored-by: Renovate Bot <renovate@mgrote.net>
Co-committed-by: Renovate Bot <renovate@mgrote.net>

.woodpecker/build.yml

@@ -7,7 +7,7 @@ variables: # https://woodpecker-ci.org/docs/usage/advanced-usage
 
 steps:
   selfhosted_push:
-    image: "woodpeckerci/plugin-docker-buildx:3.0.1"
+    image: "woodpeckerci/plugin-docker-buildx:3.1.0"
     settings:
       dockerfile: Dockerfile
       repo: registry.mgrote.net/fpm