Update dotnet-desktop.yml

Upgrade to upload-artifact@v4

Author: febinjoy

.github/workflows/dotnet-desktop.yml

@@ -109,7 +109,7 @@ jobs:
 
     # Upload the MSIX package: https://github.com/marketplace/actions/upload-a-build-artifact
     - name: Upload build artifacts
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: MSIX Package
         path: ${{ env.Wap_Project_Directory }}\AppPackages