Possibly a fix for RT.CommandLine exception on net7.0

Author: rstarkov

RT.CommandLine/RT.CommandLine.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net5.0;net7.0</TargetFrameworks>
     <DocumentationFile>$(OutputPath)\$(AssemblyName).xml</DocumentationFile>
 
     <Version>1.0.0.9999</Version>