Update WPF to build against newest released version of the SDK (.NET 6.0 Preview1)

[ryalanms]

WinForms is now building against .NET 6.0 Preview 1, and WPF cannot take WinForms updates until moving to 6.0.

Update WPF to build against newest released version of the SDK (.NET 6.0 Preview1). WPF was on 5.0.100.

Fixes #4122.

[ryalanms]

This will require one more update for platform compatibility validation. Attributes need to be added in a few more files.

[lindexi]

Do the following documents also need to be changed?

• Documentation/projects-and-assemblies.md
• eng\WpfArcadeSdk\tools\ReferenceAssembly.targets Line:55
• eng\WpfArcadeSdk\tools\SdkReferences.targets Line:205,208
• packaging\Microsoft.DotNet.Arcade.Wpf.Sdk\Microsoft.DotNet.Arcade.Wpf.Sdk.ArchNeutral.csproj Line:4
• packaging\Microsoft.DotNet.Wpf.GitHub\Microsoft.DotNet.Wpf.GitHub.ArchNeutral.csproj Line:4
• packaging\Microsoft.DotNet.Wpf.GitHub\Microsoft.DotNet.Wpf.GitHub.csproj Line:4
• packaging\Microsoft.Dotnet.Wpf.ProjectTemplates\content\WpfApplication-CSharp.template.config\template.json Line:40
• packaging\Microsoft.Dotnet.Wpf.ProjectTemplates\content\WpfApplication-VisualBasic.template.config\template.json Line:40
• packaging\Microsoft.Dotnet.Wpf.ProjectTemplates\Microsoft.DotNet.Wpf.ProjectTemplates.ArchNeutral.csproj Line:4
• packaging\Microsoft.NET.Sdk.WindowsDesktop\Microsoft.NET.Sdk.WindowsDesktop.ArchNeutral.csproj Line:4
• packaging\Microsoft.NET.Sdk.WindowsDesktop\Sdk\Sdk.props Line:20

[ryalanms]

@lindexi: Yes, there are some paths that need to remain the same for the winforms package reference.