Make this integration test work with PHPUnit 10

[nyamsprod]

Description

Make this integration test work with PHPUnit 10.

Additional context

Some changes may lead to have a new major version for this to work see https://getrector.com/blog/how-to-upgrade-to-phpunit-10-in-diffs

[dbu]

agree we should do this. if we can keep it compatible, with phpunit 9, its nice. but if it is too complicated, we can release a new minor version for that. no need for a major work, as long as usage of the integration tests does not need to change - composer dependencies will make sure a new version for phpunit 10 can not get installed with phpunit 9.

do you want to work on this? i'd be happy to review a pull request for it.