Recent version of Expo do not require config settings in app.json, app.config.js to be in expo property

#### Environment details

- OS: macOS 15
- Node.js version: 22
- npm version: 10
- `release-please` version: 4

#### Steps to reproduce

1. Create an Expo project
2. Ensure that the app.json is in the newer format i.e.
```json
{
"version": "1.0.0"
}
```
and not the old format
```json
{
"expo": {
"version": "1.0.0"
}
}
```
3. Run release please and you'll notice a crash as it's looking for version in a property that doesn't exist.
https://github.com/googleapis/release-please/blob/15c75a92761f844dfeb8dec36efbb15af6848e27/src/updaters/expo/app-json.ts#L51

Details here https://github.com/expo/fyi/blob/main/root-expo-object.md