[BuildTools.MSIX] Adding package to project yields WinAppSdkValidateAppxManifestItems error

[riverar]

Describe the bug

When attempting to add the latest BuildTools.MSIX package to a blank WinAppSDK/WinUI application, a build error occurs:

The "Microsoft.Build.Msix.AppxManifest.WinAppSdkValidateAppxManifestItems" task could not be loaded from the assembly C:\Users\Rafael.nuget\packages\microsoft.windowsappsdk\1.6.250108002\buildTransitive..\tools\net472\Microsoft.Windows.SDK.BuildTools.MSIX.dll. Could not load file or assembly 'file:///C:\Users\Rafael.nuget\packages\microsoft.windowsappsdk\1.6.250108002\tools\net472\Microsoft.Windows.SDK.BuildTools.MSIX.dll' or one of its dependencies. The system cannot find the file specified. Confirm that the declaration is correct, that the assembly and all its dependencies are available, and that the task contains a public class that implements Microsoft.Build.Framework.ITask.

Steps to reproduce the bug

1. git clone https://github.com/riverar/repro-211f09d9fccb
2. cd repro-211f09d9fccb
3. dotnet add package Microsoft.Windows.SDK.BuildTools.MSIX
4. dotnet msbuild /p:Configuration=Release /p:AppxPackageDir="MSIXOutputX64\" /p:GenerateAppxPackageOnBuild=true /p:Platform=x64 -bl
5. Observe warning/failure
6. (Optional) Review msbuild.binlog

Expected behavior

Build to succeed

Screenshots

No response

NuGet package version

Windows App SDK 1.6.3: 1.6.250108002

Packaging type

Packaged (MSIX)

Windows version

Insider Build (xxxxx)

IDE

Visual Studio 2022-preview, Other, Visual Studio 2022

Additional context