maintainer PRs still require manual approval of workflow

Copilot reviews trigger the [`Ready-for-review (collect)` workflow](https://github.com/hyperlight-dev/hyperlight/blob/main/.github/workflows/ready-for-review-label.yml#L14-L18). GitHub treats Copilot as an external actor, so our `all_external_contributors` policy requires approval.

This leaves an approval warning on maintainer PRs. [PR #1723](https://github.com/hyperlight-dev/hyperlight/pull/1723) and [run 31618809389](https://github.com/hyperlight-dev/hyperlight/actions/runs/31618809389) show the issue.

Job conditions do not help because approval happens first. Or we can remove copilot reviews entirely

Start with .github/workflows/ready-for-review-label.yml, the all_external_contributors policy, PR #1723, and run 31618809389 to confirm where approval is required. Decide whether maintainer Copilot reviews should be exempted or removed, then verify the chosen behavior no longer leaves an approval warning on maintainer PRs.

Written by the indexing model from the issue text.