[Bug]: Content files added by the package do not provide NuGetPackageId metadata

[kzu]

Version

1.50.0

Steps to reproduce

The targets file includes content items in the consuming project.

If you install (for example) System.Diagnostics.DiagnosticSource (v9, say), you will notice that the content item it provides to the consuming project, is included by nuget as follows in the project's obj\[projectname].nuget.g.props:

  <ItemGroup Condition=" '$(ExcludeRestorePackageImports)' != 'true' ">
    <Content Include="$(NuGetPackageRoot)system.diagnostics.diagnosticsource\9.0.2\contentFiles\any\net8.0\ILLink\ILLink.Descriptors.LibraryBuild.xml" Condition="Exists('$(NuGetPackageRoot)system.diagnostics.diagnosticsource\9.0.2\contentFiles\any\net8.0\ILLink\ILLink.Descriptors.LibraryBuild.xml')">
      <NuGetPackageId>System.Diagnostics.DiagnosticSource</NuGetPackageId>
      <NuGetPackageVersion>9.0.2</NuGetPackageVersion>
      <NuGetItemType>Content</NuGetItemType>
      <Pack>false</Pack>
      <Private>False</Private>
      <Link>ILLink\ILLink.Descriptors.LibraryBuild.xml</Link>
    </Content>
  </ItemGroup>

This convention allows the consumer's custom targets to act and extend the build as needed by checking (at a minimum) the NuGetPackageId to see what items are being included by which packages.

Since Playwright is not using the default mechanism for content files inclusion, this metadata is missing, making it impossible for consumers to detect these items in a reliable way.

Expected behavior

I expect the content items to at least contain the NuGetPackageId metadata, and optionally the NuGetPackageVersion.

Actual behavior

No NuGet-related metadata is provided.

Additional context

No response

Environment

- .NET Version (TFM): net8.0/9.0