Disable workload redirects for now

We are not fully certain that they are transparent and that they won't
cause unintended knock-on effects.

src/Resolvers/Microsoft.NET.Sdk.WorkloadManifestReader/WorkloadManifestReader.cs

@@ -463,7 +463,8 @@ private static BaseWorkloadDefinition ReadWorkloadDefinition(WorkloadId id, ref
                             {
                                 throw new WorkloadManifestFormatException(Strings.RedirectWorkloadHasOtherKeys, id);
                             }
-                            return new WorkloadRedirect (id, replacementId);
+                            throw new NotImplementedException("Workload redirects are not yet fully implemented");
+                            //return new WorkloadRedirect (id, replacementId);
                         }
                         var isAbstract = isAbstractOrNull ?? false;
                         if (!isAbstract && kind == WorkloadDefinitionKind.Dev && string.IsNullOrEmpty (description))