fix: Remove attestation

Got an error with this : https://github.com/visualize-admin/electricity-prices-switzerland/actions/runs/11479647067/job/31946378934

Run actions/attest-build-provenance@v1
Run actions/attest-build-provenance@f1185f1
Run actions/attest@67422f5
Error: OCIError: Error uploading artifact to container registry
Error: Error fetching https://ghcr.io/v2/ghcr.io/visualize-admin/elcom-strompreise-screenshot/manifests/sha256:3c9a8d7301595716fa94e3d8ebc4c5365f0bff16c2441c8c42cc57ccef842494 - expected 200, received 404

.github/workflows/docker.yml

@@ -78,13 +78,6 @@ jobs:
           tags: ${{ steps.meta-app.outputs.tags }}
           labels: ${{ steps.meta-app.outputs.labels }}
 
-      - name: Generate artifact attestation
-        uses: actions/attest-build-provenance@v1
-        with:
-          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME_APP}}
-          subject-digest: ${{ steps.push-app.outputs.digest }}
-          push-to-registry: true
-
       # Build screenshot
       - name: Extract metadata (tags, labels) for Docker
         id: meta-screenshot
@@ -108,10 +101,3 @@ jobs:
           push: true
           tags: ${{ steps.meta-app.outputs.tags }}
           labels: ${{ steps.meta-screenshot.outputs.labels }}
-
-      - name: Generate artifact attestation
-        uses: actions/attest-build-provenance@v1
-        with:
-          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME_SCREENSHOT}}
-          subject-digest: ${{ steps.push-app.outputs.digest }}
-          push-to-registry: true