Fix branch tests on 8.x-1.x

Fix the tests on the 8.x-1.x branch as it's blocking other changes.

Against 9.1: https://www.drupal.org/pift-ci-job/1944727

1) Drupal\Tests\metatag\Kernel\Migrate\d7\MetatagDefaultTest::testMetatag
PHPUnit\Framework\Exception: PHP Fatal error: Uncaught Exception: Serialization of 'Closure' is not allowed in Standard input code:89

Against 8.9: https://www.drupal.org/pift-ci-job/1944726

1) Drupal\Tests\metatag\Kernel\Migrate\d7\MetatagDefaultTest::testMetatag
Migration failed with source plugin exception: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'jenkins_drupal_contrib_342522.test119540620metatag_config' doesn't exist: SELECT m.instance AS instance, m.config AS config
FROM
{metatag_config} m; Array
(
)
in /var/www/html/core/lib/Drupal/Core/Database/Connection.php line 701
Failed asserting that false is true.