Enable parallel test execution via shared target

Moved the ParallelizeAttribute configuration from individual test project files to the shared Community.Toolkit.Common.targets file. This centralizes the configuration and ensures all test projects run tests in parallel by default.

Author: Sergio0694

build/Community.Toolkit.Common.targets

@@ -16,4 +16,9 @@
     <None Include="$(RepositoryDirectory)ThirdPartyNotices.txt" Pack="true" PackagePath="\" Visible="False" />
   </ItemGroup>
 
+  <!-- Run tests in parallel by default -->
+  <ItemGroup Condition="$(IsTestProject)">
+    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
+  </ItemGroup>
+
 </Project>

tests/CommunityToolkit.Common.UnitTests/CommunityToolkit.Common.UnitTests.csproj

@@ -10,10 +10,6 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
   </ItemGroup>
 
-  <ItemGroup>
-    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\..\src\CommunityToolkit.Common\CommunityToolkit.Common.csproj" />
   </ItemGroup>

tests/CommunityToolkit.Diagnostics.UnitTests/CommunityToolkit.Diagnostics.UnitTests.csproj

@@ -10,10 +10,6 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
   </ItemGroup>
 
-  <ItemGroup>
-    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\..\src\CommunityToolkit.Diagnostics\CommunityToolkit.Diagnostics.csproj" />
   </ItemGroup>

tests/CommunityToolkit.HighPerformance.UnitTests/CommunityToolkit.HighPerformance.UnitTests.csproj

@@ -10,10 +10,6 @@
     <ProjectReference Include="..\..\src\CommunityToolkit.HighPerformance\CommunityToolkit.HighPerformance.csproj" />
   </ItemGroup>
 
-  <ItemGroup>
-    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
-  </ItemGroup>
-
   <ItemGroup>
     <PackageReference Include="MSTest.TestAdapter" Version="4.0.1" />
     <PackageReference Include="MSTest.TestFramework" Version="4.0.1" />

tests/CommunityToolkit.Mvvm.DisableINotifyPropertyChanging.UnitTests/CommunityToolkit.Mvvm.DisableINotifyPropertyChanging.UnitTests.csproj

@@ -10,10 +10,6 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
   </ItemGroup>
 
-  <ItemGroup>
-    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\..\src\CommunityToolkit.Mvvm\CommunityToolkit.Mvvm.csproj" />
     <ProjectReference Include="..\..\src\CommunityToolkit.Mvvm.SourceGenerators.Roslyn4001\CommunityToolkit.Mvvm.SourceGenerators.Roslyn4001.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" PrivateAssets="contentfiles;build" />

tests/CommunityToolkit.Mvvm.Internals.UnitTests/CommunityToolkit.Mvvm.Internals.UnitTests.csproj

@@ -10,10 +10,6 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
   </ItemGroup>
 
-  <ItemGroup>
-    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\..\src\CommunityToolkit.Mvvm\CommunityToolkit.Mvvm.csproj" />
   </ItemGroup>

tests/CommunityToolkit.Mvvm.Roslyn4001.UnitTests/CommunityToolkit.Mvvm.Roslyn4001.UnitTests.csproj

@@ -14,10 +14,6 @@
     <PackageReference Include="System.Text.Json" Version="8.0.5" />
   </ItemGroup>
 
-  <ItemGroup>
-    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\CommunityToolkit.Mvvm.ExternalAssembly.Roslyn4001\CommunityToolkit.Mvvm.ExternalAssembly.Roslyn4001.csproj" />
     <ProjectReference Include="..\..\src\CommunityToolkit.Mvvm\CommunityToolkit.Mvvm.csproj" />

tests/CommunityToolkit.Mvvm.Roslyn4031.UnitTests/CommunityToolkit.Mvvm.Roslyn4031.UnitTests.csproj

@@ -14,10 +14,6 @@
     <PackageReference Include="System.Text.Json" Version="8.0.5" />
   </ItemGroup>
 
-  <ItemGroup>
-    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\CommunityToolkit.Mvvm.ExternalAssembly.Roslyn4031\CommunityToolkit.Mvvm.ExternalAssembly.Roslyn4031.csproj" />
     <ProjectReference Include="..\..\src\CommunityToolkit.Mvvm\CommunityToolkit.Mvvm.csproj" />

tests/CommunityToolkit.Mvvm.Roslyn4120.UnitTests/CommunityToolkit.Mvvm.Roslyn4120.UnitTests.csproj

@@ -19,10 +19,6 @@
     <PackageReference Include="System.Text.Json" Version="8.0.5" />
   </ItemGroup>
 
-  <ItemGroup>
-    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\CommunityToolkit.Mvvm.ExternalAssembly.Roslyn4031\CommunityToolkit.Mvvm.ExternalAssembly.Roslyn4031.csproj" />
     <ProjectReference Include="..\..\src\CommunityToolkit.Mvvm\CommunityToolkit.Mvvm.csproj" />

tests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn4001.UnitTests/CommunityToolkit.Mvvm.SourceGenerators.Roslyn4001.UnitTests.csproj

@@ -13,10 +13,6 @@
     <PackageReference Include="MSTest.TestFramework" Version="4.0.1" />
   </ItemGroup>
 
-  <ItemGroup>
-    <AssemblyAttribute Include="Microsoft.VisualStudio.TestTools.UnitTesting.ParallelizeAttribute"/>
-  </ItemGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\..\src\CommunityToolkit.Mvvm\CommunityToolkit.Mvvm.csproj" />
     <ProjectReference Include="..\..\src\CommunityToolkit.Mvvm.CodeFixers.Roslyn4001\CommunityToolkit.Mvvm.CodeFixers.Roslyn4001.csproj" />