Enabling “Editor Extension Authoring” in UI Builder doesn’t dirty the document and saving with shortcut doesn’t persist the state

Steps to reproduce:

1. Create a new project using Universal 3D template
2. Create a new UXML asset (Assets > Create > UI Toolkit > UI Document (UXML))
3. In the UI Builder Hierarchy, select the .uxml item
4. In the Inspector, under "Document Settings" enable the "Editor Extension Authoring" property
5. Click Ctrl+S/Cmd+S to save and close the UI Builder
6. Reopen the UXML asset in UI Builder
7. Observe the "Editor Extension Authoring" property

Actual results: The property does not persist after reopening; enabling it does not mark the document dirty, so Ctrl/Cmd+S has no effect

Expected results: The property remains enabled and its state is saved when using the keyboard shortcut (Ctrl/Cmd+S)

Reproducible with versions: 6000.0.69f1, 6000.3.10f1, 6000.4.0b11, 6000.5.0a8

Tested on (OS): Ubuntu 24.04, macOS 26.2

Notes:

• The state is only saved if using UI Builder’s File > Save