github.rest.issues.createComment results in "Resource not accessible by integration" error #490

I'm attempting to use github-script to post a comment to a PR during CI. Unfortunately it is failing with the error "Error: Unhandled error: HttpError: Resource not accessible by integration" when run on a PR to the main repository. When the same commit (72c2497) is run on my fork of the repository, CI passes and posts the comment without error. So far, I've tried adding the following permission settings, but none of them work for PR's against the main repository:

permissions:
  pull-requests: write

permissions:
  pull-requests: write
  issues: write

permissions: write-all

permissions:
  id-token: write
  contents: read
  issues: write
  pull-requests: write

We've also checked that "Allow all actions and reusable workflows" and "Read and write permissions" is set for the main repository's action permission settings.

Is there another permission that we need to set? Any suggestions would be appreciated! Thanks!