ToolStripTextBox renders incorrectly when hosted in MenuStrip

### .NET version

.NET 11.0.100-preview.7.26365.114 + Private dlls built from Net11/Integration-4 branch of https://github.com/KlausLoeffelmann/winforms repo

### Did it work in .NET Framework?

Does not apply - did not exist before.

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

Not support, new feature of https://github.com/dotnet/winforms/pull/14792

### Issue description

When running in **Dark Mode** with **VisualStylesMode = .NET11**, a `ToolStripTextBox` hosted in a `MenuStrip` is rendered incorrectly.

Unlike the same control hosted in a `ToolStrip`, the `MenuStrip` version displays an unexpected light-colored rectangular area on the right side of the text box. The background is not rendered using the Dark Mode color scheme, resulting in an obvious visual artifact.

### Steps to reproduce

1. Create a WinForms application.
2. Set `VisualStylesMode` to `NET11`.
3. Enable Dark Mode.
4. Add a `ToolStripTextBox` to a `MenuStrip`.
5. Run the application.