Use repository_owner instead of actor

Co-authored-by: Copilot <[email protected]>

Author: PythonGermany

.github/workflows/docker-cd.yml

@@ -52,7 +52,7 @@ jobs:
         id: meta
         uses: docker/metadata-action@v5
         with:
-          images: ${{ env.REGISTRY }}/${{ github.actor }}/${{ env.IMAGE_NAME }}
+          images: ${{ env.REGISTRY }}/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}
 
       # Build and push Docker image with Buildx (don't push on PR)
       # https://github.com/docker/build-push-action