Symfony version(s) affected: 5.1.0

Description
I use the symfony/string component as standalone package. After the update to version 5.1.0 the following error occured.

Error : Interface 'Symfony\Contracts\Translation\LocaleAwareInterface' not found

How to reproduce
Create a new package without any requirements and require the string component. Create a new instance of the AsciiSlugger and the error occured.

Possible Solution
Maybe the package should require the translation-contracts.