feat: Bump UWPSyncGenerator version

Author: MartinZikmund

src/Directory.Build.props

@@ -82,6 +82,7 @@
   </ItemGroup>
 
   <PropertyGroup>
+    <!-- When updating this in the future, please also update CSharpLangVersion constant in src\Uno.UWPSyncGenerator\Generator.cs -->
     <LangVersion>11.0</LangVersion>
 
     <!-- Roslyn generation is enabled by default for all uno projects (inside uno.ui only) -->

src/Uno.UWPSyncGenerator/Generator.cs

@@ -13,6 +13,8 @@ namespace Uno.UWPSyncGenerator
 {
 	abstract class Generator
 	{
+		private const string CSharpLangVersion = "11.0";
+		
 		private const string net461Define = "NET461";
 		private const string AndroidDefine = "__ANDROID__";
 		private const string iOSDefine = "__IOS__";
@@ -1755,7 +1757,7 @@ private static Compilation InnerLoadProject(string projectFile, string targetFra
 								//{ "BuildingInsideVisualStudio", "true" },
 								{ "SkipUnoResourceGeneration", "true" }, // Required to avoid loading a non-existent task
 								{ "DocsGeneration", "true" }, // Detect that source generation is running
-								{ "LangVersion", "8.0" },
+								{ "LangVersion", CSharpLangVersion },
 								//{ "DesignTimeBuild", "true" },
 								//{ "UseHostCompilerIfAvailable", "false" },
 								//{ "UseSharedCompilation", "false" },