AEM Mocks Core Maven Build fails

the missing dependency can be found at
https://repo.adobe.com/nexus/content/groups/public/org/apache/commons/commons-imaging/1.0-R1534292/

also adobe is in progress if migrating all it's artifacts to maven central some are still only found in the adobe maven repos
https://wcm.io/maven.html

switching to 1.0-alpha1/2 is not an option as we need to stay in sync with the version included by adobe in AEM, which is unfortunately only a snapshot that was never released - the referenced version 1.0-R1534292 comes as close as possible.