Use PHP 8.4

What's Changed

• Make CI passable by @webignition in #42
• Use local php cs fixer by @webignition in #46
• Swap PSR-12 for PER-latest by @webignition in #47
• Use phpstan ^2 by @webignition in #48
• Use PHP 8.4 by @webignition in #49
• Use phpunit ^12 by @webignition in #50

Full Changelog: 3.0...4.0