`Up-to-date protobuf` action should use authenticated requests

[StephenButtolph]

The buf check occasionally gets rate limited because we do not perform any authentication.

For example: https://github.com/ava-labs/avalanchego/actions/runs/9487445671/job/26144106471

See: https://docs.github.com/rest/overview/resources-in-the-rest-api#rate-limiting

[github-actions]

This issue has become stale because it has been open 60 days with no activity. Adding the lifecycle/frozen label will cause this issue to ignore lifecycle events.