update directory LangVersion as latest

Jesn · echofool · commit 86120e971ca5 · 2021-08-24T13:24:24.000+08:00
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
@@ -1,7 +1,7 @@
 <Project>
   <PropertyGroup>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
-    <LangVersion>8.0</LangVersion>
+    <LangVersion>latest</LangVersion>
     <TargetFramework>net5.0</TargetFramework>
     <Nullable>enable</Nullable>
     <GeneratePackageOnBuild>false</GeneratePackageOnBuild>
