Null pointer exception in uswds_register_theme_hooks()

The uswds_register_theme_hooks() hook implementation makes an assumption that the theme registry entries contain process functions or preprocess functions array elements defined. However, these elements are present only if corresponding callbacks have been defined for a given hook. As such, uswds_register_theme_hooks() runs into a NULL pointer exception when executing the code on line 125:
!in_array($callback, $entry["$type functions"].

I am experiencing this on Drupal 11.2, so maybe there are changes in Drupal API related to this.