Update RazorCompilation.targets for new SDK

Author: rynowak

src/Components/blazor/samples/HostedInAspNet.Server/HostedInAspNet.Server.csproj

@@ -1,7 +1,18 @@
-<Project Sdk="Microsoft.NET.Sdk.Web">
+<Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
     <TargetFramework>netcoreapp3.0</TargetFramework>
+
+    <!--
+      This is a workaround that's needed because Microsoft.AspNetCore.App includes the OLD Razor.Design
+      package and MSBuild support. We don't want those features to be used with the new SDK. Basically
+      combining netcoreapp3.0 and and Razor.Design will result in duplicate assembly attributes.
+
+      See: https://github.com/aspnet/AspNetCore/issues/6182
+
+      This workaround can be removed when this project is converted to the shared framework.
+    -->
+    <GenerateProvideApplicationPartFactoryAttribute>false</GenerateProvideApplicationPartFactoryAttribute>
   </PropertyGroup>
 
   <ItemGroup>

src/Components/blazor/samples/MonoSanity/MonoSanity.csproj

@@ -6,7 +6,6 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore" Version="$(MicrosoftAspNetCoreAppPackageVersion)" />
-    <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="$(MicrosoftAspNetCoreRazorDesignPackageVersion)" />
   </ItemGroup>
 
   <ItemGroup>

src/Components/samples/ComponentsApp.Server/ComponentsApp.Server.csproj

@@ -6,7 +6,6 @@
 
     <ItemGroup>
       <PackageReference Include="Microsoft.AspNetCore" Version="$(AspNetCorePackageVersion)" />
-      <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="$(MicrosoftAspNetCoreRazorDesignPackageVersion)" />
     </ItemGroup>
 
     <ItemGroup>

src/Components/src/Microsoft.AspNetCore.Components.Build/Microsoft.AspNetCore.Components.Build.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp3.0</TargetFrameworks>
+    <TargetFramework>netcoreapp3.0</TargetFramework>
     <Description>Build mechanism for ASP.NET Core Components.</Description>
     <OutputType>Exe</OutputType>
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
@@ -60,7 +60,7 @@
       repositorycommit=$(RepositoryCommit);</NuspecProperties>
     </PropertyGroup>
     <ItemGroup>
-      <_TargetFramework Include="$(TargetFrameworks)" />
+      <_TargetFramework Include="$(TargetFramework)" />
     </ItemGroup>
     <MSBuild Projects="$(MSBuildProjectFullPath)" Targets="Publish" Properties="TargetFramework=%(_TargetFramework.Identity)" />
   </Target>