relay.config.json autodetect broken

I'm using Relay v13.2.0, and can't get it to read from `relay.config.json` when running `relay-compiler`, as [documented on relay-compiler](https://github.com/facebook/relay/tree/main/packages/relay-compiler). I've [forked](https://github.com/chillu/relay-examples/commits/relay.config.json-autodetect-broken) the `relay-examples` repo to demonstrate this behaviour, after upgrading the repo to the newest Relay release and moving the existing config from `package.json` to a new `relay.config.json`.

```
git clone -b relay.config.json-autodetect-broken git@github.com:chillu/relay-examples.git
cd relay-examples/todo
yarn
yarn build

yarn run v1.22.17
$ relay-compiler
[ERROR] No config found.
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
```

Reproduce the report from the relay-examples fork by running yarn in todo and then yarn build, starting with the relay-compiler entry point and the documented relay.config.json behavior. Compare the new relay.config.json with the former package.json configuration; done means relay-compiler autodetects the file and the build completes without “No config found.”

Written by the indexing model from the issue text.