Request Parameters of type KeyDataPair are replaced by instances of type NameValuePair when WebRequest#getParameters is called.
This introduces issues with Spring Boot 3 and especially spring-test 6 where the getParameters method is called instead of getRequestParameters as it has been in spring-test 5.x

See 39c58d2#r93713845

I've already a proposal how this can be fixed. Pull Request incoming :-D