Body:
- Updated property type for $User in Auth
- Scoped $user to string, array, int in __construct method in Auth
- Method return types updated from void, int, array, bool to ?Control in Auth and Registrar
- Invalid php stan comments remove from phpstan-baseline.neon
- PhpStan version updated in .phive/phars.xml
- Quiqqer-major-version remove from .gitlab-ci.yml
- Added chdir and system function imports in EventHandler

Updated the package versions in composer.json. Changed the version specifications for
"quiqqer/core", "quiqqer/frontend-users", "simplito/elliptic-php", and "kornrunner/keccak". This is
to ensure compatibility with the latest versions of these packages. Please ensure to run a composer
update after this change.

BREAKING CHANGE: quiqqer/core v2

fix: update URLs and file paths in composer.json

See merge request !2

Updated the urls in composer.json file to use https instead of http. Also, fixed the file paths to
normal forward slashes for better compatibility across different OS.