Changelog creation not retained after deletion. Same as #7333

[nahun]

NetBox version

v3.0.8

Python version

3.8

Steps to Reproduce

This is the same as #7333, but looks like the issue is back.

Testing on https://demo.netbox.dev shows this behavior

1. create new prefix object
2. validated CREATE changelog entry is present
3. delete newly created prefix object
4. validated DELETE changelog entry is present, but CREATE changelog entry is gone

Expected Behavior

Changelog to keep previous creation entry if the object is deleted

Observed Behavior

Once object is deleted, changelog for creation is gone

[jeremystretch]

Well I could swear this was fixed under #7333, but going back to v3.0.4 I can see it was not.

[jeremystretch]

Ok, I think I see what happened. The root cause was the addition of the GenericRelation from ChangeLoggingMixin to ObjectChange. I obviated this with my change to the GraphGQL type in 6bccb6d, but never actually removed the GenericRelation from the mixin. 😞 The good news is that it's an easy fix!

And just for proof that it really is fixed this time, here's a changelog showing the creation, update, and deletion of a prefix:

Thanks @nahun for following up on this!