Symfony version(s) affected: >= 5.3.0 (just tested 5.3.0, 5.3.1, 5.3.2-dev#9485292)

Description
While running tests with Symfony 5.3 I'm getting this error:
RuntimeException: The autoloader expected class "Symfony\Component\Messenger\Transport\Doctrine\DoctrineTransportFactory" to be defined in file "/home/travis/build/craue/CraueGeoBundle/vendor/composer/../symfony/symfony/src/Symfony/Component/Messenger/Transport/Doctrine/DoctrineTransportFactory.php". The file was found but the class was not in it, the class name or namespace probably has a typo.

I'm not actively using the Messenger component.

How to reproduce
Run the test suite of that bundle with latest dependencies.

Possible Solution
I could work around the issue by removing symfony/symfony from the require-dev section in composer.json and explicitly defining the needed deps instead, but that would require further modifications to my test setup (to work with a range of Symfony versions) I'd like to avoid.