CI with GitHub Actions

GitHub Actions make CI so much easier that it would be a shame not to take advantage of it.

PHP Code Sniffer

Why not? The code should have a uniform standard, if only to make it easier to read.

PHP 8

It's time to switch to PHP 8. It's been with us long enough, it would be a shame not to take advantage of its capabilities.

One of the BCs in PHP is to change the isolation of static properties within a class. That's why the properties cache had to be rewritten, so if Config doesn't work on your higher PHP, use the new version.

The use and behaviour has remained identical, so you are not at risk of BC.