Library generation failed (3ebf090)

See [failed job](https://github.com/googleapis/google-cloudevents-java/actions/runs/18152168340)

Start with the failed job linked in the issue: https://github.com/googleapis/google-cloudevents-java/actions/runs/18152168340. Read its logs to identify where library generation failed and which generated artifact or step is affected. Done means the library generation job completes successfully.

索引モデルが issue の本文から書いたものです。