chore(deps): adopt Gouroboros release containing localtxsubmission decoder fix

## Summary

Adopt a released Gouroboros version that contains the local transaction
submission decoder hardening.

## Acceptance criteria

- Update the Gouroboros dependency to `v0.202.2` or a later release containing
the fix.
- Run the repository's relevant Go tests and lint checks.
- Keep the existing dependency-update pull request additive if it remains open.

This issue tracks downstream dependency adoption only; implementation details
remain in the upstream change.