Update docker.io/woodpeckerci/plugin-docker-buildx Docker tag to v3.2.0 (#3540)

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This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
|
[docker.io/woodpeckerci/plugin-docker-buildx](https://codeberg.org/woodpecker-plugins/docker-buildx)
([source](https://codeberg.org/woodpecker-plugins/docker-buildx.git)) |
minor | `3.1.0` -> `3.2.0` |

---

### Release Notes

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

###
[`v3.2.0`](https://codeberg.org/woodpecker-plugins/docker-buildx/releases/tag/v3.2.0)

[Compare
Source](https://codeberg.org/woodpecker-plugins/docker-buildx/compare/v3.1.0...v3.2.0)

##### Features

- Allow `default_tag` to be empty
([#&#8203;145](https://togithub.com/woodpecker-plugins/docker-buildx/issues/145))
WARNING: not battle-tested (as I did not have a use case and testing
repo). Please expect issues along the way.
- Add `SOURCE_DATE_EPOCH` build_arg
([#&#8203;130](https://togithub.com/woodpecker-plugins/docker-buildx/issues/130))
- Add `provenance` config setting
([#&#8203;139](https://togithub.com/woodpecker-plugins/docker-buildx/issues/139))
- Add `secrets` config setting
([#&#8203;135](https://togithub.com/woodpecker-plugins/docker-buildx/issues/135))

##### Dependencies

-   chore(deps): update docker/buildx-bin docker tag to v0.13.1
-   chore(deps): update docker docker tag to v25.0.4

</details>

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.woodpecker/docker.yaml

@@ -3,7 +3,7 @@ variables:
   - &node_image 'docker.io/node:21-alpine'
   - &xgo_image 'docker.io/techknowlogick/xgo:go-1.22.1'
   - &xgo_version 'go-1.21.2'
-  - &buildx_plugin 'docker.io/woodpeckerci/plugin-docker-buildx:3.1.0'
+  - &buildx_plugin 'docker.io/woodpeckerci/plugin-docker-buildx:3.2.0'
   - &platforms_release 'linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/386,linux/amd64,linux/ppc64le,linux/riscv64,linux/s390x,freebsd/arm64,freebsd/amd64,openbsd/arm64,openbsd/amd64'
   - &platforms_server 'linux/arm/v7,linux/arm64/v8,linux/amd64,linux/ppc64le,linux/riscv64'
   - &platforms_preview 'linux/amd64'