Cannot Delete Landscape with World Partition enabled

If you delete all the LandscapeStreamingProxies under the landscape object the parent landscape object can be deleted.

Not a regression checked in Version: 5.1.0-23058290+++UE5+Release-5.1

1. Open any project in Unreal Editor
2. Create a new Open World level
3. In the outliner select the Landscape object
4. try to delete it

Result: You cannot delete it

Expected Result: You can delete it