I think it should be generating with org.kie.kogito.dmn.rest.KogitoDMNResult. Is this a bug? I still couldn't locate org.kie.kogito.rest.DMNResult.
In maven dependency, this is the version I'm using for code gen.
<dependency>
<groupId>org.kie.kogito</groupId>
<artifactId>kogito-codegen-api</artifactId>
<version>1.44.1.Final</version>
</dependency>