Any unit test that calls createArrayDataSet() fails

mod_collaborate has a unit test that does exactly this. And it fails with:

1) mod_collaborate_recording_counter_testcase::test_get_recording_counts
Error: Class 'PHPUnit\DbUnit\DataSet\DefaultTableMetaData' not found
/home/marcus/workspace/latrobe/lib/phpunit/classes/arraydataset.php:61
/home/marcus/workspace/latrobe/lib/phpunit/classes/advanced_testcase.php:190
/home/marcus/workspace/latrobe/mod/collaborate/tests/recording_counter_test.php:56
/home/marcus/workspace/latrobe/lib/phpunit/classes/advanced_testcase.php:80

To re-run: vendor/bin/phpunit "mod_collaborate_recording_counter_testcase" mod/collaborate/tests/recording_counter_test.php

We first thought the issue was with a non-properly installed DbUnit but upon digging further, it's a typo in core which is causing this issue.