"Error: Input required and not supplied: github-token"

All of a sudden I’ve been getting this error.

/action/node_modules/@actions/core/lib/core.js:94
        throw new Error(`Input required and not supplied: ${name}`);
              ^

Error: Input required and not supplied: github-token
    at Object.getInput (/action/node_modules/@actions/core/lib/core.js:94:15)
    at file:///action/index.js:28:15
    at ModuleJob.run (node:internal/modules/esm/module_job:154:23)
    at async Loader.import (node:internal/modules/esm/loader:166:24)
    at async Object.loadESM (node:internal/process/esm_loader:68:5)

E.g. https://github.com/mdn/content/pull/2964/checks?check_run_id=2066177430

I haven’t touched my personal access tokens. And auto-merge hasn’t been upgraded on the project in 3 months. It just stopped working today all of a sudden. Sample PR: https://github.com/mdn/content/pull/2964

I don’t know if it’s a bug or user-error. Or a problem with GitHub Actions changing under our feet.

I did try generating a new access token (using the public_repo scope) to see if that would make it work. But arguably, it’s a long shot because the error says the token isn’t supplied.