PHP 8.4 Symfony 7.3

What's Changed

• Bump PHP requirement to ^8.4
• upgrade Symfony components to ^7.3
• Upgrade PHPUnit to ^12.3
• Switch to humbug/box (^4.6) for phar building
• Add GitHub action with PhpUnit and PHPStan

Full Changelog: v0.5.0...v1.0.0