Laravel 12 upgrade

[Tofandel]

Follow up of #2755

With the upgrade of larastan a few lint issues popped up, the phpcsfixer config and phpstan config required small updates

Then they were ran, only a few manual fixes were done (eg fireCmsEvent, the method exists would always be true in all supported laravel versions so removed)

[Braunson]

@ifox Hoping we can get this in soon :)

[ifox]

Thank you so much @Braunson and @Tofandel, added PHP 8.4 to the tests matrix and finally merged this. Stay tuned for the release. We know this is way overdue, but we're still here and excited to ship new releases!