I am happy to announce that phpstan-drupal and drupal-check are Drupal 9 and PHP 8 ready! Both projects have CI pipelines running tests and analysis to make sure they're compatible as we start the journey for Drupal 10 (😱 already? I know!)
Florida DrupalCamp sponsored 20 hours of development. Since my funding is from the community, I have been working on these projects via a live stream on Twitch every Wednesday.