refactor: 更新 C# 版本

ArgoZhang · ArgoZhang · commit 20034c6b025f · 2025-10-23T11:16:29.000+08:00
diff --git a/Directory.Build.props b/Directory.Build.props
@@ -11,7 +11,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <LangVersion>latest</LangVersion>
+    <LangVersion>preview</LangVersion>
     <AccelerateBuildsInVisualStudio>true</AccelerateBuildsInVisualStudio>
     <SuppressNETCoreSdkPreviewMessage>true</SuppressNETCoreSdkPreviewMessage>
   </PropertyGroup>
