Virtualization causes ListBoxItems to stretch incorrectly

### Description

If UI virtualization is enabled for ListBox/ListView, the width/content layout of items becomes incorrect when the width is reduced.

https://github.com/user-attachments/assets/b143c5a2-5aef-4e37-824f-d4149c6e5585

### Reproduction Steps

https://github.com/CodingOctocat/ListBoxItemWidthIssue

### Expected behavior

At any time, the width of ListBoxItems can be correctly stretched to fit.

### Actual behavior

When the ListBox width is too small, the ListBoxItem width becomes incorrect, requiring manual scrolling of the ListBox to trigger UI redrawing.

### Regression?

_No response_

### Known Workarounds

Data binding is required to bind the width of the ListBoxItem to the width of the virtualization container.

```xaml

<Setter Property="HorizontalContentAlignment" Value="Stretch" />
<Setter Property="Margin" Value="0,4" />

<!-- Known Workarounds -->
<!--<Setter Property="Width"
Value="{Binding ActualWidth, RelativeSource={RelativeSource AncestorType={x:Type VirtualizingStackPanel}}}" />-->

```

### Impact

_No response_

### Configuration

- .NET9
- Win11 24h2
- x64

### Other information

_No response_