Library generation failed (d706482)

See [failed job](https://github.com/googleapis/google-cloudevents-java/actions/runs/18611242586)

Start with the linked failed GitHub Actions job for generation d706482 and inspect its failure output. Trace the reported generation failure to the relevant project entry point; the work is done when library generation completes successfully, but the issue does not identify the affected file or test.

Written by the indexing model from the issue text.