replace ImageSharp.Texture dependency

with MonoGame's DxtUtil static class, since we only need DXT decompression.

Author: Krzyhau

Converter/FEZRepacker.Converter.csproj

@@ -27,7 +27,6 @@
   <ItemGroup>
     <PackageReference Include="System.Text.Json" Version="7.0.1" />
     <PackageReference Include="SixLabors.ImageSharp" Version="2.1.3" />
-    <PackageReference Include="SixLabors.ImageSharp.Textures" Version="0.0.0-alpha.0.139" />
   </ItemGroup>
 
 </Project>