Upgrading from WindowsAppSDK 1.7 to 1.8 causes APPX1101 build errors

@manodasanW is already working on this.

Since Sep 12, 2025.

### Describe the bug

After upgrading to WindowsAppSDK 1.8, my project has three APPX1101 errors, saying the payload contains two or more files with the same destination path.

`Payload contains two or more files with the same destination path 'Microsoft.Windows.SDK.NET.dll'. Source files:
C:\Users\.....\.nuget\packages\microsoft.windows.sdk.net.ref\10.0.22621.57\lib\net8.0\Microsoft.Windows.SDK.NET.dll
C:\Users\.....\.nuget\packages\microsoft.windows.sdk.net.ref\10.0.22621.48\lib\net8.0\Microsoft.Windows.SDK.NET.dll`

`Payload contains two or more files with the same destination path 'Microsoft.Win32.SystemEvents.dll'. Source files:
C:\Users\.....\.nuget\packages\microsoft.win32.systemevents\9.0.9\runtimes\win\lib\net9.0\Microsoft.Win32.SystemEvents.dll
C:\Users\.....\.nuget\packages\microsoft.win32.systemevents\9.0.9\lib\net9.0\Microsoft.Win32.SystemEvents.dll`

and

```
Payload contains two or more files with the same destination path 'System.Management.dll'. Source files:
C:\Users\.....\.nuget\packages\system.management\7.0.2\runtimes\win\lib\net7.0\System.Management.dll
C:\Users\.....\.nuget\packages\system.management\7.0.2\lib\net7.0\System.Management.dll
```

I have tried cleaning bin/obj folders and nuget cache - unfortunately nothing seems to resolve the error. If I revert back to 1.7, the project builds fine.

### Steps to reproduce the bug

1. Upgrade projects to WindowsAppSDK 1.8
2. Build solution
3. APPX1101 errors

Unfortunately I'm not exactly sure what about my projects is causing these issues to be able to repro in a demo project? One of the projects in the solution is a CSWinRT component, so maybe that?

### Expected behavior

Solution builds correctly

### Screenshots

_No response_

### NuGet package version

Windows App SDK 1.8.0: 1.8.250907003

### Packaging type

Packaged (MSIX)

### Windows version

Windows 11 version 24H2 (26100, June 2025 Update)

### IDE

Visual Studio 2022

### Additional context

_No response_