https://www.drupal.org/node/3272354
Filter tests should not rely on Classy [#3272354] | Drupal.org
May 29, 2022 - Problem/Motivation Because of [#3083275] and Classy being deprecated in Drupal 9 + removed in Drupal 10,: Tests that aren't specifically testing Classy yet...
should notrely onfiltertestsclassy