chore: Update cosign

.github/workflows/docker-publish.yml

@@ -34,7 +34,7 @@ jobs:
       # https://github.com/sigstore/cosign-installer
       - name: Install cosign
         if: github.event_name != 'pull_request'
-        uses: sigstore/cosign-installer@v2.8.1
+        uses: sigstore/cosign-installer@v3.7.0
 
       # Workaround: https://github.com/docker/build-push-action/issues/461
       - name: Setup Docker buildx
@@ -76,8 +76,4 @@ jobs:
       # https://github.com/sigstore/cosign
       - name: Sign the published Docker image
         if: ${{ github.event_name != 'pull_request' }}
-        env:
-          COSIGN_EXPERIMENTAL: "true"
-        # This step uses the identity token to provision an ephemeral certificate
-        # against the sigstore community Fulcio instance.
         run: cosign sign ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${{ steps.build-and-push.outputs.digest }}