Add .NET 7 Support for Blazor views (#2254)

Author: mattleibow

source/SkiaSharp.Views.Blazor/SkiaSharp.Views.Blazor/nuget/build/net6.0/SkiaSharp.Views.Blazor.Local.props

@@ -5,8 +5,11 @@
     <WasmBuildNative Condition="'$(WasmBuildNative)' == ''">true</WasmBuildNative>
   </PropertyGroup>
 
-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetFrameworkVersion)' != '' and $([MSBuild]::VersionEquals($(TargetFrameworkVersion), '6.0'))">
     <NativeFileReference Include="$(SkiaSharpStaticLibraryPath)\2.0.23\*.a" />
   </ItemGroup>
+  <ItemGroup Condition="'$(TargetFrameworkVersion)' != '' and $([MSBuild]::VersionEquals($(TargetFrameworkVersion), '7.0'))">
+    <NativeFileReference Include="$(SkiaSharpStaticLibraryPath)\3.1.12\st\*.a" />
+  </ItemGroup>
 
 </Project>

source/SkiaSharp.Views.Blazor/SkiaSharp.Views.Blazor/nuget/build/net6.0/SkiaSharp.Views.Blazor.props

@@ -6,9 +6,12 @@
     <_SkiaSharpViewsBlazorStaticAssetsRoot>$([System.IO.Path]::GetFullPath('$(MSBuildThisFileDirectory)..\..\staticwebassets'))\</_SkiaSharpViewsBlazorStaticAssetsRoot>
   </PropertyGroup>
 
-  <ItemGroup>
+  <ItemGroup Condition="'$(TargetFrameworkVersion)' != '' and $([MSBuild]::VersionEquals($(TargetFrameworkVersion), '6.0'))">
     <NativeFileReference Include="$(SkiaSharpStaticLibraryPath)\2.0.23\*.a" />
   </ItemGroup>
+  <ItemGroup Condition="'$(TargetFrameworkVersion)' != '' and $([MSBuild]::VersionEquals($(TargetFrameworkVersion), '7.0'))">
+    <NativeFileReference Include="$(SkiaSharpStaticLibraryPath)\3.1.12\st\*.a" />
+  </ItemGroup>
 
   <ItemGroup>
     <_TempStaticWebAsset Include="$(_SkiaSharpViewsBlazorStaticAssetsRoot)*.js" />