[Dark Mode] the DropDownButton of Type Here not in dark mode in DemoConsole application

### .NET version

.NET 9.0.100-rc.2.24453.35

### Did it work in .NET Framework?

No

### Did it work in any of the earlier releases of .NET Core or .NET 5+?

This is a new feature Dark Mode: https://github.com/dotnet/winforms/pull/11857

### Issue description

The **DropDownButton** of **Type Here** not in dark mode.

### Steps to reproduce

1. Clone the [DemoConsole](https://github.com/dotnet/winforms/tree/main/src/System.Windows.Forms/tests/IntegrationTests/DesignSurface/DemoConsole) in Winforms repo
2. Enable Dark mode by adding below code lines in the Program.cs file under DemoConsole project
```
#pragma warning disable WFO5001
Application.SetColorMode(SystemColorMode.Dark);
```
3. Build and run the DemoConsole project
4. Observe the color for the **DropDownButton** of **Type Here** item