Scancode not passed to TSF

### Description

The TextServiceManager does not pass scancode to Cicero/TSF

### Reproduction Steps

https://github.com/dotnet/wpf/blob/7f005faa89e79b0b1fa1cb2c21283bab7916c092/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/TextServicesManager.cs#L232-L235

type anything using IME

### Expected behavior

The scancode to be properly populated, e.g. from `keyArgs.Scancode`

### Actual behavior

scancode seen in `ITfKeyEventSink.On[Test]KeyDown` is always 0

### Regression?

no

### Known Workarounds

reconstruct from virtual key

### Impact

text services relying on scancodes do not work in WPF

### Configuration

.NET 10/4.8, Windows 11, x64

### Other information

_No response_