Refine #if conditions around use of attributes

Author: AArnott

src/Nerdbank.GitVersioning.Tasks/AssemblyVersionInfo.cs

@@ -25,7 +25,7 @@ public class AssemblyVersionInfo : Microsoft.Build.Utilities.Task
         /// </summary>
         /// <see href="https://github.com/dotnet/Nerdbank.GitVersioning/issues/346" />
         private const string CompilerDefinesAroundGeneratedCodeAttribute = "NETSTANDARD || NETFRAMEWORK || NETCOREAPP";
-        private const string CompilerDefinesAroundExcludeFromCodeCoverageAttribute = "NETFRAMEWORK || NETCOREAPP || NETSTANDARD2_0 || NETSTANDARD2_1";
+        private const string CompilerDefinesAroundExcludeFromCodeCoverageAttribute = "NET40_OR_GREATER || NETCOREAPP2_0_OR_GREATER || NETSTANDARD2_0_OR_GREATER";
         private const string FileHeaderComment = @"------------------------------------------------------------------------------
  <auto-generated>
      This code was generated by a tool.