How to reproduce:
1. Open the “Entities_System_Indentation_Bug“ project
2. Open the “SampleScene”
3. Enter Play Mode
4. Open the Entities Systems window (Window > Entities > Systems)
5. Expand at least 2 child Systems and observe the Entities Systems window

Expected result: child systems are indented depending on their depth
Actual result: child systems are not indented at all

Reproduced with: 1.0.0-exp.8 (2022.2.20f1, 2023.1.0b17, 2023.2.0a15), 1.0.8 (2022.2.20f1, 2023.1.0b17, 2023.2.0a15)
Could not test with: 0.17.0-preview.41 (2022.2.20f1, 2023.1.0b17, 2023.2.0a15) (Package scripting errors), 0.17.0-preview.41 (2020.3.48f1, 2021.3.25f1), 1.0.8 (2020.3.48f1, 2021.3.25f1) (Entities Package is not supported)

Reproduced on: Windows 11

Notes:
1. The expected result can be found in the Entities System window reference: https://docs.unity3d.com/Packages/com.unity.entities@1.0/manual/editor-systems-window.html
2. Actual result is attached in the internal comments
3. Can be reproduced in a newly created project