fix: pass docker_username, docker_password to publish stage

.woodpecker.yml

@@ -1,6 +1,7 @@
 # SPDX-FileCopyrightText: 2023 Tobias Schmidl
 #
 # SPDX-License-Identifier: AGPL-3.0-or-later
+
 ---
 variables:
   - &repo 'git.schmidl.dev/schtobia/buildimage'
@@ -12,7 +13,10 @@ steps:
       repo: *repo
       registry: git.schmidl.dev
       dry_run: true
-#      output: type=oci,dest=${CI_REPO_OWNER}-buildimage.tar
+    when:
+      branch:
+        exclude: [ master ]
+      event: push
 
   publish-next-agent:
     image: woodpeckerci/plugin-docker-buildx
@@ -23,6 +27,10 @@ steps:
       registry: git.schmidl.dev
       dockerfile: dockerfile
       platforms: linux/amd64,linux/arm64/v8
+      username:
+        from_secret: docker_username
+      password:
+        from_secret: docker_password
     when:
       branch: master
       event: push