Enables Symonfy 8.x 🚀

What's Changed

• Update PHPUnit to 10.x, clean up package structure, bump requirements by @mpdude in #55
• Add composer-require-checker in GitHub Actions by @mpdude in #56
• Allow Symfony 8.x to be used by @mpdude in #57

Full Changelog: 3.4.2...3.5.0