Library overrides crashed with on trying to access the interface root panel. The root panel should not be exposed through RNA, but also accessing its `position` property should be allowed.
Several fixes here:
- Fix `position` property getter when the item has no parent panel (i.e. the root panel).
- Avoid infinite loops in the greedy override comparison: exclude the loopback `parent` property.
- Don't return the root panel via the `parent` property in the first place, just return nullptr.
Pull Request: https://projects.blender.org/blender/blender/pulls/111755
2a94a99605