Resolve "Project import error, User expected, got Hash"

What does this MR do?

1. We always export author_id, so it will either match a user or use the default user
2. If we have to leave a note about details from the original author in case it’s not found, we should export author and add logic to do this in relation_factory

In this case, we just need 1.

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer

Closes #57712 (closed)