Pass the test when running using the 6.0 SDK against 17.4.0 or higher. This should not flow to 7.0.1xx

Author: marcpopMSFT

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

@@ -353,6 +353,12 @@ static int Last2DigitsTo0(int versionBuild)
         [InlineData("net6.0")]
         public void It_can_publish_runtime_specific_apps_with_library_dependencies_self_contained(string targetFramework) {
 
+            // There's a bug when using the 6.0 SDK with 17.4 but we have limited control over the VS version used in helix
+            Version.TryParse(TestContext.Current.ToolsetUnderTest.MSBuildVersion, out Version msbuildVersion);
+            Version.TryParse("17.4.0", out Version maximumVersion);
+            if (msbuildVersion >= maximumVersion)
+                return;
+
             // create a basic library and a basic app, reference the library from the app and then
             // publish the app with a RID specified and self-contained.
             // verify that no warnings about missing the --self-contained flag are emitted.