Update to net48 and condition NativeAOT on .NET Core

Directory.Build.props

@@ -19,9 +19,7 @@
     </PropertyGroup>
 
     <PropertyGroup Condition=" $([MSBuild]::IsOsPlatform('Windows')) ">
-        <TargetFrameworks>$(TargetFrameworks);net8.0-windows10.0.22000</TargetFrameworks>
-        
-        <TargetFrameworks Condition=" $(EnableNetFXTarget) == 'true' ">$(TargetFrameworks);net461;</TargetFrameworks>
+        <TargetFrameworks>$(TargetFrameworks);net8.0-windows10.0.22000;net48</TargetFrameworks>
     </PropertyGroup>
 
     <Choose>

UIXcontrols/UIXcontrols.csproj

@@ -18,4 +18,4 @@
             <LogicalName>RCDATA.resources</LogicalName>
         </EmbeddedResource>
     </ItemGroup>
-</Project>
+</Project>

UIXrender/UIXrender.csproj

@@ -6,7 +6,9 @@
         <RootNamespace>Microsoft.Iris.Render</RootNamespace>
         <GenerateAssemblyInfo>true</GenerateAssemblyInfo>
         <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    </PropertyGroup>
 
+    <PropertyGroup Condition=" $(TargetFrameworkIdentifier) == '.NETCoreApp' ">
         <PublishAot>true</PublishAot>
 
         <!-- Required for PublishAot to emit an actual exporting shared library (.dll/.so)