Incompatibility with Laravel 8, 9

[vientoquesurcalosmares]

When updating Laravel to version 8 it asks to use dragonmantank/cron-expression version 3, but this version is incompatible with the liebig/cron package, please update to use in the most recent versions of laravel, thanks!

[liebig]

I would be very grateful to receive a pull request for this.