Use PHP 8.4, service-client ^8

What's Changed

• Make CI builds passable by @webignition in #91
• Use PHP 8.4 by @webignition in #92
• Use phpunit ^12 by @webignition in #93
• Use phpstan ^2.1 by @webignition in #94
• Use symfony/uid ^7.3 by @webignition in #95
• Use service-client ^8, results-client ^9 by @webignition in #96

Full Changelog: 4.1...5.0