Workflow dispatch from opensim-core fails due to credentials issue

[nickbianco]

The error message from GitHub Actions:

Run codex-/return-dispatch@v1
  with:
    token: ***
    ref: refs/heads/main
    repo: opensim-gui
    owner: opensim-org
    workflow: build-on-core-pr.yml
    workflow_timeout_seconds: 300
  env:
    GH_TOKEN: ***
Fetching Workflow ID for build-on-core-pr.yml...
Error: getWorkflowId: An unexpected error has occurred: Bad credentials - https://docs.github.com/rest
Error: Failed: Bad credentials - https://docs.github.com/rest
Warning: Does the token have the correct permissions?
Error: Bad credentials - https://docs.github.com/rest