Update LangVersion to 13.0 for improved compatibility

Author: tg123

Directory.Build.props

@@ -26,7 +26,7 @@
     <SymbolPackageFormat>snupkg</SymbolPackageFormat>
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
     <AllowedOutputExtensionsInPackageBuildOutputFolder>$(AllowedOutputExtensionsInPackageBuildOutputFolder);.pdb</AllowedOutputExtensionsInPackageBuildOutputFolder>
-    <LangVersion>11.0</LangVersion>
+    <LangVersion>13.0</LangVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(GITHUB_ACTIONS)' == 'true'">