Consolidate GlobalUsings imports around tooling

Author: Arlodotexe

.github/workflows/config/Directory.Build.props

@@ -36,8 +36,4 @@
     <IsPublishable>true</IsPublishable>
     <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
   </PropertyGroup>
-
-  <ItemGroup>
-    <Compile Include="$(RepositoryDirectory)tooling\GlobalUsings.cs" />
-  </ItemGroup>
 </Project>

ProjectHeads/App.Head.props

@@ -1,5 +1,8 @@
 <!-- Common props for any deployable app project head. -->
 <Project>
+  <Import Project="$(MSBuildThisFileDirectory)\..\MultiTarget\Extra.props" />
+  <Import Project="$(ToolingDirectory)\MultiTarget\GlobalUsings.props" />
+
   <!-- Shared project -->
   <Import Project="$(ToolingDirectory)\CommunityToolkit.App.Shared\CommunityToolkit.App.Shared.projitems" Label="Shared" />
 

ProjectHeads/Tests.Head.props

@@ -1,4 +1,7 @@
 <Project>
+  <Import Project="$(MSBuildThisFileDirectory)\..\MultiTarget\Extra.props" />
+  <Import Project="$(ToolingDirectory)\MultiTarget\GlobalUsings.props" />
+
   <!-- Source generators -->
   <ItemGroup Condition="'$(IsWinAppSdk)' != 'true'">
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.11.0" PrivateAssets="all" />