Major Description
Due to the lack of documentation it was never clear whether org.apache.maven.project.MavenProject.getAttachedArtifacts() is mutable or not. Components used or abused this collection. The change was done in 3.8.x in a patch release which was unfortunately and make things obvious. To better address the breaking situation this change will be partially reverted in 3.8.x and 3.9.0, but documented in 4.0.0 that the collection is read-only. A proper solution to remove attached is desired in the future.
