PhpUnit was recently bumped to 9.5, which removes assertArraySubset. This is blocking merges on PageTriage, which relied on ArraySubset directly as a Constraint.
Related log output from https://integration.wikimedia.org/ci/job/quibble-vendor-mysql-php74-noselenium-docker/59563/console:
09:52:20 1) ApiPageTriageListTest::testCreateDraftPage 09:52:20 Error: Class 'PHPUnit\Framework\Constraint\ArraySubset' not found
Will need to remove all references to ArraySubset whenever possible for tests to work again. I have a patch ready but will need someone to review and merge.