Set assets manifest metadata for assets that get shipped with .NET release (#98824)

* add metadata to manifest

* set in ItemDefinitionGroup

* remove from items

* comment

Author: MilenaHristova

src/installer/prepare-artifacts.proj

@@ -23,6 +23,8 @@
   </PropertyGroup>
   <Import Project="../tools/Sign.props" Sdk="Microsoft.DotNet.Arcade.Sdk" />
 
+  <Import Project="$(RepositoryEngineeringDir)Publishing.props" Condition="Exists('$(RepositoryEngineeringDir)Publishing.props')" />
+
   <UsingTask TaskName="GenerateChecksums" AssemblyFile="$(InstallerTasksAssemblyPath)" />
 
   <PropertyGroup>
@@ -56,6 +58,16 @@
     <ManifestBuildData Include="AzureDevOpsBranch=$(BUILD_SOURCEBRANCH)" />
   </ItemGroup>
 
+  <!-- 
+    Set metadata for assets that are not marked as NonShipping. 
+    This is used to determine if the asset should be shipped as part of .NET release.
+  -->
+  <ItemDefinitionGroup>
+    <ItemsToPush>
+      <ManifestArtifactData Condition="'$(ProducesDotNetReleaseShippingAssets)' == 'true'">DotNetReleaseShipping=true</ManifestArtifactData>
+    </ItemsToPush>
+  </ItemDefinitionGroup>
+
   <!--
     Run Arcade's signing project directly. The 'eng/Signing.props' extensibility props file checks
     if '$(<StageName>)' == 'true' and points Arcade to the correct files.