Describe the bug

Text is incorrectly trimmed when I use emoji or Japanes characters and TextTrimming is set to PrefixCharacterElipsis

To Reproduce

MainWindow.axaml:

<StackPanel>
    <TextBox Text="{Binding Greeting}" />
    <TextBlock Text="{Binding Greeting}" MaxWidth="200" TextTrimming="PrefixCharacterEllipsis" Background="Red"/>
</StackPanel>

MainWindowViewModel.cs:

    public partial class MainWindowViewModel : ViewModelBase
    {
        [ObservableProperty]
        private string _greeting = "Welcome to Avalonia! どうもありがとうございます";
    }

When I do not use special characters it looks good:

Adding Emoji cause issues:

With the text: טקסט בשפה עברית אמור להיות מוצג מימין לשמאל is even worse:

Expected behavior

Text is trimmed correctly. We see begining and end of the text

Avalonia version

11.2.3, 11.3.0, 11.3.2, 12.0.999-cibuild0057790-alpha

OS

Windows

Additional context

No response