nullable is deprecated

There was another ticket logged regarding this error message but perhaps this one was missed or re-introduced.

PHP Deprecated: Drupal\ai_image_alt_text\Controller\GenerateAltText::generate(): Implicitly marking parameter $file as nullable is deprecated, the explicit nullable type must be used instead in /app/web/modules/contrib/ai_image_alt_text/src/Controller/GenerateAltText.php on line

Cheers Dan