Rector is a PHP tool that automates refactoring your code to take advantage of the latest language-level features in PHP or automated usages of deprecated code when upgrading your dependencies.

If you haven't seen or heard, the Drupal 10 readiness effort is heavy underway. Wait. Drupal 10? Yeah. Drupal 8 will be at its end of life in two months, and Drupal 10 is to be released sometime next year.