Other .query API methods include projects in projectPHIDs, but currently not repository.create.

Use case: on an external system consuming stories through webhooks post, dispatch notifications about stories to different places according the projects.

To achieve this, we need to gather more information about stories, like the project attached to an item, which is straightforward for tasks or commits, but less for revisions. For revisions, we would like to get the list of projects attached to the repo in addition of the (rare) projects attached directly to the diff.