There is a feature dependency circle between content and workflow since CMS-12462.
Until CMS-12462, it was always the workflow that was accessing the content, but the restauration of a content (called directly on the content) now invoke the workflow. Making the content depend on workflow and the workflow depends on content.
Currently, the issue is circumvented by not declaring the feature dependency to workflow on the trash.content feature. But this is a hack and only works because every features are loaded at startup and the ContentTrashElementType is an extension of a LazyInitialized extension point.
It required adding the dependency to cms/workflow to every test that was only needing cms/factories until now.