ci: fix docker auth using frankchine and DOCKERHUB_TOKEN secret

.gitea/workflows/build-push.yaml

@@ -24,7 +24,7 @@ jobs:
       - name: Set up Docker config
         run: |
           mkdir -p .docker
-          echo "{\"auths\":{\"https://index.docker.io/v1/\":{\"auth\":\"$(echo -n \"${{ secrets.REGISTRY_USERNAME }}:${{ secrets.REGISTRY_PASSWORD }}\" | base64 | tr -d '\n')\"}}}" > .docker/config.json
+          echo "{\"auths\":{\"https://index.docker.io/v1/\":{\"auth\":\"$(echo -n \"frankchine:${{ secrets.DOCKERHUB_TOKEN }}\" | base64 | tr -d '\n')\"}}}" > .docker/config.json
 
       - name: Build and Push with Kaniko
         uses: docker://gcr.io/kaniko-project/executor:debug