Actions/stale v9 encounters a 404

I am trying to deploy actions/stale@v9 to keep some handle on the number of stale PRs open against repos. The action successfully spins up and makes it through 15 actions before dying with this error:

::error::HttpError: 404 page not found%0A
::error::404 page not found%0A

My workflow looks like this:

---
name: Stale PR Cleanup

on:
  workflow_dispatch:
  schedule:
    - cron: "@daily"

jobs:
  stale:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/stale@v9
        with:
          days-before-stale: 30
          stale-pr-message: "This PR will be closed in 7 days due to inactivity. Add a comment or remove the 'Stale' label to keep it open."
          days-before-issue-stale: -1

It is unclear why this is encountering a 404, or even what it was doing when it tried to access the nonexistent resource. I have set the debug secrets listed for actions/stale, but it doesn’t seem to have increased verbosity any.

Any advice is appreciated.