config/config php wrong note related to config-cache

### Bug Report



|    Q        |   A
|------------ | ------
| Version(s)  | x.y.z

#### Summary

Line 9-10 
// To enable or disable caching, set the `ConfigAggregator::ENABLE_CACHE` boolean in
// `config/autoload/local.php`.
this is not valid anymore 
let's clarify who and where and when is generating the config-cache file