Toolkit requires FrameworkReference to be updated in WinUI target

[nickrandolph]

Current behavior

When adding toolkit to a WinUI project, it's necessary to update the frameworkreference - hard for developers to diagnose

Expected behavior

Toolkit should be able to be added to winui project without affecting compilation or requiring additional steps

How to reproduce it (as minimally and precisely as possible)

Create new WinUI application
Add reference to toolkit
Build will fail complaining dependencies compiled with newer framework version

Proposed Fix##

Remove these lines

uno.toolkit.ui/src/Directory.Build.targets

Lines 32 to 42 in f311d14

	<ItemGroup>
	<!--
	If you encounter this error message:
	error NETSDK1148: A referenced assembly was compiled using a newer version of Microsoft.Windows.SDK.NET.dll. Please update to a newer .NET SDK in order to reference this assembly.
	This means that the two packages below must be aligned with the "build" version number of
	the "Microsoft.Windows.SDK.BuildTools" package above, and the "revision" version number
	must be the highest found in https://www.nuget.org/packages/Microsoft.Windows.SDK.NET.Ref.
	-->
	<FrameworkReference Update="Microsoft.Windows.SDK.NET.Ref" RuntimeFrameworkVersion="10.0.22621.28" />
	<FrameworkReference Update="Microsoft.Windows.SDK.NET.Ref" TargetingPackVersion="10.0.22621.28" />
	</ItemGroup>