When using a FluentWinUI3 style ComboBox, if the ComboBox model is dynamically reloaded with a smaller or larger model, the ComboBox popup does not resized at all.

Attached example reproduces the issue.

Steps to reproduce:
1. Open each combo box. Observe each popup is correctly resized relative to the content of the model
2. Click the "Update comboBox model" button to load a smaller list model
3. Open each combo box. Observe the FluentWinUI3 comboBox popup is not resized, whereas the Windows comboBox popup is correctly resized.
4. Click the "Update comboBox model" button to load larger list model
5. Open each combo box. Observe the FluentWinUI3 comboBox popup is not resized, whereas the Windows comboBox popup is correctly resized.