Cosign bundles are now required for release signing (#406)

Author: sfotony

.goreleaser.yml

@@ -27,6 +27,7 @@ signs:
       - sign-blob
       - --output-certificate=${certificate}
       - --output-signature=${signature}
+      - --bundle=${signature}.bundle
       - ${artifact}
       - --yes  # needed on cosign 2.0.0+
     artifacts: checksum