Deploying war into servlet container (like tomcat) is a legacy approach.
Usually, Spring Boot application is packaged as Jar, which has inside it a servlet container and is executed as any java program ( java -jar note-service.jar). In this case, you don't need an image with tomcat and java image will be enough.
@SpringBootTest is an integration test and should be used only if spring configuration should be tested (like controllers or custom repository methods). In your case usual JUnit runner can be used (which will faster)
@DaTa annotation is not recommended for using with hibernate entities. In your example it is fine but there could be problems with autogenerated hashCode and equals for entities with lazy-loaded fields and @tostring.