PHP 8.4

[nickschuch]

Adding an issue to track PHP 8.4 support.

https://www.php.net/releases/8.4/en.php

I'm happy to work on this. I'm not really sure where to start.

[jmjoy]

You can try to add 8.4 CI to see if it can pass CI.

https://github.com/phper-framework/phper/blob/master/.github/workflows/ci.yml