branch with simple test by @sgiehl:
This fixes the deprecation warning of a dependency:
Package container-interop/container-interop is abandoned, you should avoid using it. Use psr/container instead.
Migration guide: https://github.com/PHP-DI/PHP-DI/blob/6.0.0/doc/migration/6.0.md
This will also be needed to include the fix for PHP 8 compatibility: https://github.com/PHP-DI/PHP-DI/issues/727