Publish conflicts when using agora_rtc_sdk with .NET 9 - Multiple duplicate files with same relative path

[architpoddar-if]

Issue Summary

When attempting to publish a .NET 9 WPF application that uses the agora_rtc_sdk NuGet package (version 4.2.6.19-alpha.1), the publish process fails due to duplicate file conflicts.

Error Message

Found multiple publish output files with the same relative path: 
C:\Users\{User}\.nuget\packages\agora_rtc_sdk\4.2.6.19-alpha.1\build\x64\net40\agorartc.dll, 
C:\Users\{User}\.nuget\packages\agora_rtc_sdk\4.2.6.19-alpha.1\build\x64\netcoreapp20\agorartc.dll, 
C:\Users\{User}\.nuget\packages\agora_rtc_sdk\4.2.6.19-alpha.1\build\x64\net40\agorartc.pdb, 
C:\Users\{User}\.nuget\packages\agora_rtc_sdk\4.2.6.19-alpha.1\build\x64\netcoreapp20\agorartc.pdb

Root Cause

The NuGet package includes both .NET Framework 4.0 (net40) and .NET Core 2.0 (netcoreapp20) versions of the same files (agorartc.dll and agorartc.pdb). When publishing a .NET 9 application, both versions are included in the publish output, causing filename conflicts.

Environment

• Target Framework: .NET 9 (net9.0-windows)
• Project Type: WPF Application
• NuGet Package Version: 4.2.6.19-alpha.1
• Build Action: Folder Publish
• OS: Windows

Current Workaround

We've implemented a custom MSBuild target to exclude the .NET Framework 4.0 versions:

<Target Name="RemoveAgoraDuplicates" BeforeTargets="ComputeFilesToPublish">
  <ItemGroup>
    <ResolvedFileToPublish Remove="@(ResolvedFileToPublish)" 
                           Condition="$([System.String]::Copy('%(ResolvedFileToPublish.FullPath)').Contains('net40\agorartc'))" />
  </ItemGroup>
</Target>

Expected Behavior

The publish process should automatically select the appropriate version of the native libraries based on the target framework without requiring manual intervention or custom MSBuild targets.