removes docker artifact step

.github/workflows/docker-image.yml

@@ -4,6 +4,10 @@ on:
   release:
     types: [published]
 
+env:
+  REGISTRY: docker.io
+  IMAGE_NAME: tholzheim/wbmigrator
+
 jobs:
   push_to_registry:
     name: Push Docker image to Docker Hub
@@ -37,11 +41,4 @@ jobs:
           file: ./Dockerfile
           push: true
           tags: ${{ steps.meta.outputs.tags }}
-          labels: ${{ steps.meta.outputs.labels }}
-
-      - name: Generate artifact attestation
-        uses: actions/attest-build-provenance@v1
-        with:
-          subject-name: ${{ steps.meta.outputs.tags }}
-          subject-digest: ${{ steps.push.outputs.digest }}
-          push-to-registry: true
+          labels: ${{ steps.meta.outputs.labels }}