Merge pull request #3562 from BDisp/v1_2598_self-contained-net80-fix

Fixes #2598. Trying to run self-contained application on Ubuntu 22 (Linux-x64), error regarding libdl.so

Terminal.Gui/ConsoleDrivers/CursesDriver/UnmanagedLibrary.cs

@@ -256,7 +256,7 @@ namespace Unix.Terminal {
 		/// to avoid the dependency on libc-dev Linux.
 		/// </summary>
 		static class CoreCLR {
-#if NET7_0
+#if NET6_0_OR_GREATER
 			// Custom resolver to support true single-file apps
 			// (those which run directly from bundle; in-memory).
 			//	 -1 on Unix means self-referencing binary (libcoreclr.so)

Terminal.Gui/Terminal.Gui.csproj

@@ -20,7 +20,7 @@
     <DebugType>portable</DebugType>
   </PropertyGroup>
   <PropertyGroup>
-    <TargetFrameworks>net472;netstandard2.0;netstandard2.1;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net472;netstandard2.0;netstandard2.1;net6.0;net7.0;net8.0</TargetFrameworks>
     <RootNamespace>Terminal.Gui</RootNamespace>
     <AssemblyName>Terminal.Gui</AssemblyName>
     <SuppressNETCoreSdkPreviewMessage>true</SuppressNETCoreSdkPreviewMessage>