Notebook runner CI doesn't work on forks

[grst]

When someone creates a PR from a fork, the CI does not have permission to add commits to the branch.

To my knowledge, the only real way to solve this is to develop a github application.

For now, it is easiest to add someone who makes a PR to this repo and ask them to push to a local branch.

CC @flying-sheep

[flying-sheep]

I recently made a GitHub application: https://github.com/apps/spencer-hobson

It was relatively easy. Manually, we use it like this:

- name: Get bot token
  id: create_token
  uses: tibdex/github-app-token@v2
  with:
    app_id: ${{ secrets.SPENCER_APP_ID  }}
    private_key: ${{ secrets.SPENCER_PRIVATE_KEY }}

- name: Clone repo
  uses: actions/checkout@v4
  with:
    token: ${{ steps.create_token.outputs.token }}
    fetch-depth: 0
    filter: blob:none

- name: Commit autofixes
  uses: stefanzweifel/git-auto-commit-action@v5
  with:
    commit_message: "chore: auto-fix eslint errors"
    commit_user_name: spencer-hobson[bot]
    # This uses the anonymous identity record number you can get via:
    # https://api.github.com/users/spencer-hobson[bot]
    commit_user_email: 149329160+spencer-hobson[bot]@users.noreply.github.com

but of course that only works in repos that have access to the private key, so we need to figure out how to make the app do its thing with a central installation.