Update Woodpecker .release.yml to v3

Author: MikiDi

.woodpecker/.release.yml

@@ -1,10 +1,13 @@
-pipeline:
+steps:
   release:
-    image: plugins/docker
+    image: woodpeckerci/plugin-docker-buildx
     settings:
       repo: "${CI_REPO_OWNER##mu-}/${CI_REPO_NAME}"
       tags: "${CI_COMMIT_TAG##v}"
-    secrets: [ docker_username, docker_password ]
+      username:
+        from_secret: docker_username
+      password:
+        from_secret: docker_password
 when:
-  event: tag
-  ref: refs/tags/v*
+  - event: tag
+    ref: refs/tags/v*