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

.woodpecker/build.yml

@@ -29,7 +29,7 @@ steps:
 
   docker-dryrun:
     depends_on: vendor
-    image: woodpeckerci/plugin-docker-buildx:3.2.1
+    image: woodpeckerci/plugin-docker-buildx:6.0.4
     settings:
       dockerfile: Dockerfile
       platforms: linux/amd64
@@ -99,7 +99,7 @@ steps:
 
   docker-next:
     depends_on: vendor
-    image: woodpeckerci/plugin-docker-buildx:3.2.1
+    image: woodpeckerci/plugin-docker-buildx:6.0.4
     settings:
       registry: codeberg.org
       dockerfile: Dockerfile
@@ -116,7 +116,7 @@ steps:
 
   docker-tag:
     depends_on: vendor
-    image: woodpeckerci/plugin-docker-buildx:3.2.1
+    image: woodpeckerci/plugin-docker-buildx:6.0.4
     settings:
       registry: codeberg.org
       dockerfile: Dockerfile