Spring Boot 3 compatibility

[Undergrounder]

Is your feature request related to a problem? Please describe. Spring boot 2.x, the version used in the examples, is out of Open Source Support (OSS) and for that reason, is an invalid option for implementing a productive extension using the CommerceTools SDK. We have tried using Spring Boot 3.2.4, but the validation contraints are ignored. The CommerceTools SDK uses currently javax.* annotations instead of the new jakarta.* ones, but Spring 3.x expects the jakarta.* annotations. A change to use additionally the javax.* constraints doesn't seem to be possible. More issues may appear, as we are just starting to implement the extension.

Describe the solution you'd like A new SDK version is released that is compatible with Spring Boot 3.2.4. The examples in the SDK are updated and using the new Spring Boot version.

Describe alternatives you've considered Not using the CommerceTools Java SDK or not using Spring Boot.

Additional context https://spring.io/projects/spring-boot#support