Issue #3279788 by alexpott: PHP 7.3 testing on Drupal 9.4.x and 9.5.x is...

Issue #3279788 by alexpott: PHP 7.3 testing on Drupal 9.4.x and 9.5.x is broken due to \Drupal\Tests\RequirementsPageTrait::assertRequirementSummaries() assuming Seven is the update.php theme

(cherry picked from commit 23e599ba)