Error "NullReferenceException UnityEditor.SceneView.OnGU" is thrown when deleting the child prefab in the Scene view

How to reproduce:
1. Open the project “IN_29357”
2. Open the “Goblin_01” prefab
3. Select any child prefab in the Scene view
4. Delete it

Expected result: no error in the Console
Actual result: “NullReferenceException” error in the Console

Reproducible with: 2021.2.0b15, 2021.3.17f1, 2022.1.0a14
Not reproducible with: 2021.2.0b14, 2022.2.5f1, 2023.1.0b1
Couldn’t test with: 2020.3.44f1 (due to compiler errors and missing scripts in prefab)
Fixed in: 2022.1.0a15

Reproducible on: Windows 10 Pro

Note: not reproducible if deleting child prefab through Hierarchy

Workaround: delete prefabs through Hierarchy instead of Scene view