When a document is deleted, even with filesystem attachments enabled, the content of the attachments is stored in the database.

This problem has existed since the very beginning and was accidentally discovered when debugging XWIKI-10610. When an attachment is deleted, AttachmentRecycleBinStore.saveToRecycleBin() is called, which if FSAttach is enabled, means the deleted attachment is stored elsewhere in the filesystem. However, if the document is deleted outright, saveToRecycleBin() is never called, instead the document is "exported" to XML with the attachment content included and then stored in the DeletedDocument database table, defeating the purpose of filesystem attachments.