Merge pull request #27943 from dotnet/marcpopMSFT-warnonoostargeting6.0.1xx

Expand existing EOL warning to target 5.0

Author: marcpopMSFT

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.EolTargetFrameworks.targets

@@ -20,7 +20,7 @@ Copyright (c) .NET Foundation. All rights reserved.
     receive servicing updates and security fixes.
   -->
   <ItemGroup>
-    <_EolNetCoreTargetFrameworkVersions Include="1.0;1.1;2.0;2.1;2.2;3.0" />
+    <_EolNetCoreTargetFrameworkVersions Include="1.0;1.1;2.0;2.1;2.2;3.0;5.0" />
   </ItemGroup>
 
   <Target Name="_CheckForEolTargetFrameworks" AfterTargets="_CheckForUnsupportedNETCoreVersion"

src/Tests/Microsoft.NET.Build.Tests/GivenThatWeWantToTargetEolFrameworks.cs

@@ -23,6 +23,7 @@ public GivenThatWeWantToTargetEolFrameworks(ITestOutputHelper log) : base(log)
         [InlineData("netcoreapp1.0")]
         [InlineData("netcoreapp3.0")]
         [InlineData("netcoreapp2.1")]
+        [InlineData("net5.0")]
         public void It_warns_that_framework_is_out_of_support(string targetFrameworks)
         {
             var testProject = new TestProject()