Don't try to create fork network memberships for forks of forks
What does this MR do?
This makes sure the
CreateForkNetworkMembershipsRange does not get rescheduled for fork network links for which the fork network cannot be created.
Why was this MR needed?
Otherwise the background migration would keep being rescheduled but it would never complete, because the
ForkNetworkMember-rows it requires will never be created.
Does this MR meet the acceptance criteria?
- Changelog entry added, if necessary
- Tests added for this feature/bug
- Has been reviewed by Database