Use Skia in windows interop test + remove old hacks for old wpf control

samples/interop/WindowsInteropTest/Program.cs

@@ -16,12 +16,7 @@ namespace WindowsInteropTest
             System.Windows.Forms.Application.SetCompatibleTextRenderingDefault(false);
             AppBuilder.Configure<App>()
                 .UseWin32()
-                .UseDirect2D1()
+                .UseSkia()
-                .With(new Win32PlatformOptions
-                {
-                    UseWindowsUIComposition = false,
-                    ShouldRenderOnUIThread = true // necessary for WPF
-                })
                 .SetupWithoutStarting();
             System.Windows.Forms.Application.Run(new SelectorForm());
         }

samples/interop/WindowsInteropTest/WindowsInteropTest.csproj

@@ -8,6 +8,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\..\src\Avalonia.Diagnostics\Avalonia.Diagnostics.csproj" />
+    <ProjectReference Include="..\..\..\src\Skia\Avalonia.Skia\Avalonia.Skia.csproj" />
     <ProjectReference Include="..\..\..\src\Windows\Avalonia.Win32.Interoperability\Avalonia.Win32.Interoperability.csproj" />
     <ProjectReference Include="..\..\ControlCatalog\ControlCatalog.csproj" />
   </ItemGroup>

src/Windows/Avalonia.Win32.Interoperability/Avalonia.Win32.Interoperability.csproj

@@ -10,7 +10,6 @@
   <ItemGroup>
     <ProjectReference Include="..\..\..\packages\Avalonia\Avalonia.csproj" />
     <ProjectReference Include="..\Avalonia.Win32\Avalonia.Win32.csproj" />
-    <ProjectReference Include="..\Avalonia.Direct2D1\Avalonia.Direct2D1.csproj" />
   </ItemGroup>
 
   <Import Project="..\..\..\build\NullableEnable.props" />