Use PHP 8.4, service-client ^8

What's Changed

• Make CI builds passable by @webignition in #147
• Use PHP 8.4 by @webignition in #148
• Use phpstan ^2.1 by @webignition in #150
• Use symfony/uid ^7.3 by @webignition in #151
• Use service-client ^8 by @webignition in #152

Full Changelog: 8.1...9.0