CsWinRT 2.1.3

This is a minor release with a set of fixes for reported issues since 2.1.1.

C#/WinRT package:
https://www.nuget.org/packages/Microsoft.Windows.CsWinRT/2.1.3

What's Changed

• Add NuGet.config by @manodasanW in #1728
• Treat init-only properties as cannot write by @hez2010 in #1730
• Fix source generator issues by @manodasanW in #1732
• Fix issue in WPF scenarios where our source generator was getting ran twice by @manodasanW in #1731
• Fix GetEnumerator when C# enumerator gets passed to native and back by @manodasanW in #1735
• Detect when property expressions are used by @manodasanW in #1737
• Fix ordering of targets impacting WPF scenarios by @manodasanW in #1738

Full Changelog: 2.1.1.240807.2...2.1.3.240909.1