Micrsoft.UI.Xaml 2.8.6 not able to build for release sideloading (WebView2 WinUI2)

### Describe the bug

Not able to build a `release` sideloading app with the latest version of `Micrsoft.UI.Xmal` (2.8.6).

`Debug` builds work fine, only seeing issues with `release` builds

Downgrading `Micrsoft.UI.Xmal` to `2.8.2` fixes the issue.

### Steps to reproduce the bug

1. Set up a new project following https://learn.microsoft.com/en-us/microsoft-edge/webview2/get-started/winui2
2. Add the latest version of `Microsoft.UI.Xaml` which is `2.8.6`
3. Create app package for sideloading > when selecting the packages to create, keep both `x86` and `x64` ticked, but update the solution configuration from `debug` to `release`
4. Errors when building with:
```
Payload contains two or more files with the same destination path 'System.IO.MemoryMappedFiles.dll', but they have different content. Source files:
C:\Program Files (x86)\Microsoft SDKs\UWPNuGetPackages\runtime.win10-x86.microsoft.netcore.universalwindowsplatform\6.2.14\runtimes\win10-x86\lib\uap10.0.15138\System.IO.MemoryMappedFiles.dll
C:\Program Files (x86)\Microsoft SDKs\UWPNuGetPackages\runtime.win10-x86-aot.microsoft.netcore.universalwindowsplatform\6.2.14\runtimes\win10-x86-aot\lib\uap10.0.15138\System.IO.MemoryMappedFiles.dll
```

Note - `debug` builds work fine

### Expected behavior

_No response_

### Screenshots

_No response_

### NuGet package version

None

### Windows version

_No response_

### Additional context

_No response_

Start with the WebView2 WinUI2 setup linked in the issue and reproduce the release sideloading build using Microsoft.UI.Xaml 2.8.6, with both x86 and x64 selected. Compare it with version 2.8.2 and investigate the duplicate System.IO.MemoryMappedFiles.dll sources; done means the release package builds without that conflict.

Written by the indexing model from the issue text.