"Unset All" on variables doesn't visually refresh the Variables section until another change is made or the element is reselected

Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Create a new Visual Element in the Hierarchy (UI Toolkit > Standard Elements > Visual Element)
3. In the editing stage's Hierarchy, select the VisualElement
4. In the Inspector, add a few variables in the Variables section (e.g. Float, Color, Length)
5. Right-click the Variables category foldout (or an individual variable) in the Inspector and select "Unset All"

Actual results: The variables are removed from the underlying data, but the Variables section in the Inspector does not visually update/refresh to reflect this

Expected results: The Variables section should immediately refresh in the editing stage and show the variables as unset right after selecting "Unset All"

Reproducible with versions: 6000.6.0b6, 6000.7.0a3

Can’t test with versions: 6000.0.80f1, 6000.3.21f1, 6000.5.6f1 (due to no editing stage feature)