switching to C# 12

Author: arturcic

build/Directory.Build.props

@@ -6,7 +6,7 @@
         <OutputPath>..\..\run\</OutputPath>
         <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
         <Nullable>enable</Nullable>
-        <LangVersion>11</LangVersion>
+        <LangVersion>12</LangVersion>
         <NoWarn>NU1604</NoWarn>
         <ImplicitUsings>enable</ImplicitUsings>
     </PropertyGroup>

src/Directory.Build.props

@@ -22,7 +22,7 @@
         <WarningsAsErrors>$(WarningsAsErrors);RS0016;RS0017;RS0022;RS0024;RS0025;RS0026;RS0027</WarningsAsErrors>
 
         <DebugType>embedded</DebugType>
-        <LangVersion>11</LangVersion>
+        <LangVersion>12</LangVersion>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <SatelliteResourceLanguages>en</SatelliteResourceLanguages>