PHP Deprecated warnings in PHP 8

[james2doyle]

PHP Deprecated:  {closure:Oddvalue\LaravelDrafts\LaravelDraftsServiceProvider::packageRegistered():63}():
Implicitly marking parameter $publisherMorphName as nullable is deprecated, the explicit
nullable type must be used instead in /Users/me/Sites/mywebsite/vendor/oddvalue/laravel-
drafts/src/LaravelDraftsServiceProvider.php on line 63

I can submit a PR to fix this issue if this would be helpful for you

[oddvalue]

A PR would be much appreciated otherwise it will take me a while to get to this.
Thanks!

[alessioacella]

up