Acceptance tests summary comment not added to the PR from forks

[davidgamez]

Describe the bug

The acceptance tests summary is not added to the PR when the action is triggered in forks.
The following error is visible in the logs:

(node:1) UnhandledPromiseRejectionWarning: HttpError: Resource not accessible by integration
    at /node_modules/@octokit/request/dist-node/index.js:66:23
    at processTicksAndRejections (internal/process/task_queues.js:95:5)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:1) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:1) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Example:

• PR -> feat: rename unused_parent_station rule to unused_station #1959
• GitHub action -> https://github.com/MobilityData/gtfs-validator/actions/runs/13128106708/job/36650937663?pr=1959

Steps/Code to Reproduce

• Create a fork with a non-contributor user
• Create a PR that triggers the acceptance tests

Expected Results

The acceptance tests summary comment is added to the PR.

Actual Results

The acceptance tests summary comment is not added and an error is visible in the logs of the compare-output action.

Screenshots

No response

Files used

No response

Validator version

N/A

Operating system

N/A

Java version

No response

Additional notes

No response