chore(deps): update woodpeckerci/plugin-docker-buildx docker tag to v6

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [woodpeckerci/plugin-ready-release-go](https://github.com/woodpecker-ci/plugin-ready-release-go) | minor | `3.1.4` -> `3.2.0` |

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### 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 becomes conflicted, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

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 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

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This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
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Reviewed-on: #38
Co-authored-by: renovate-bot <renovate@ocram85.com>
Co-committed-by: renovate-bot <renovate@ocram85.com>

.woodpecker/ci.yml

@@ -5,7 +5,7 @@ when:
       - ${CI_REPO_DEFAULT_BRANCH}
 
 variables:
-  - &build_plugin 'woodpeckerci/plugin-docker-buildx:5.2.2'
+  - &build_plugin 'woodpeckerci/plugin-docker-buildx:6.0.0'
   # deployment targets
   # TODO: Disabled docker hub target until first release is ready / Rate Limits
   - &publish_repos 'ocram85/plugin-gitea-package,gitea.ocram85.com/plugins/gitea-package'

.woodpecker/release-hepler.yml

@@ -11,7 +11,7 @@ when:
 
 steps:
   release-helper:
-    image: woodpeckerci/plugin-ready-release-go:3.1.4
+    image: woodpeckerci/plugin-ready-release-go:3.2.0
     settings:
       debug: true
       git_email: noreply@ocram85.com