Debug docker.io login

Author: robertlemke

.github/workflows/docker.build.yaml

@@ -55,8 +55,8 @@ jobs:
       - name: Login to Docker Hub
         uses: docker/login-action@v3
         with:
-          username: ${{ secrets.DOCKER_IO_REGISTRY_USER }}
-          password: ${{ secrets.DOCKER_IO_REGISTRY_PASSWORD }}
+          username: ${{ secrets.DOCKER_IO_REGISTRY_USER_TEST }}
+          password: ${{ secrets.DOCKER_IO_REGISTRY_PASSWORD_TEST }}
 
       - name: Login to Google Artifacts Registry
         uses: docker/login-action@v3