remove avalonia reference to try to fix skiasharp versioning error

Author: Charles Roddie

CSharpMath.Rendering.Tests/CSharpMath.Rendering.Tests.csproj

@@ -1,8 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <ItemGroup>
     <Compile Include="..\CSharpMath.CoreTests\_Helpers\ApproximateAssertions.cs" Link="ApproximateAssertions.cs" />
-    <ProjectReference Include="..\CSharpMath.Avalonia\CSharpMath.Avalonia.csproj" />
     <ProjectReference Include="..\CSharpMath.SkiaSharp\CSharpMath.SkiaSharp.csproj" />
-    <PackageReference Include="Avalonia.Skia" Version="$(AvaloniaVersion)" />
   </ItemGroup>
 </Project>

CSharpMath.Rendering.Tests/TestRendering.cs

@@ -19,7 +19,7 @@ public TestRenderingFixture() {
       // Pre-initialize typefaces to speed tests up
       BackEnd.Fonts.GlobalTypefaces.ToString();
       // Needed by Avalonia tests!
-      global::Avalonia.Skia.SkiaPlatform.Initialize();
+      //global::Avalonia.Skia.SkiaPlatform.Initialize();
     }
     // https://www.codecogs.com/latex/eqneditor.php
     static string ThisFilePath([CallerFilePath] string? path = null) =>

CSharpMath.Rendering.Tests/TestRendering_Avalonia.cs

@@ -1,8 +1,8 @@
-using AvaloniaColor = Avalonia.Media.Color;
+//using AvaloniaColor = Avalonia.Media.Color;
 
 namespace CSharpMath.Rendering.Tests {
   using System.IO;
-  using Avalonia;
+  //using Avalonia;
   using FrontEnd;
 
 #if false // Avalonia tests are failing owing to versioning issues. When Avalonia support is updated, this test should be re-enabled.