Partially revert "do not include testing artifacts in aggregated javadoc"

This reverts commit 2da11fa but keeps the version bump of the javadoc plugin

Author: mtf90

pom.xml

@@ -966,9 +966,6 @@ limitations under the License.
                         <reports>
                             <report>aggregate</report>
                         </reports>
-                        <configuration>
-                            <skippedModules>learnlib-annotation-processor,learnlib-learner-it-support,learnlib-learning-examples,learnlib-test-support</skippedModules>
-                        </configuration>
                     </reportSet>
                 </reportSets>
             </plugin>