remove sealed from ModelProvider

packages/http-client-csharp/generator/Microsoft.Generator.CSharp/src/Providers/ModelProvider.cs

@@ -15,7 +15,7 @@
 
 namespace Microsoft.Generator.CSharp.Providers
 {
-    public sealed class ModelProvider : TypeProvider
+    public class ModelProvider : TypeProvider
     {
         private const string AdditionalBinaryDataPropsFieldDescription = "Keeps track of any properties unknown to the library.";
         private readonly InputModelType _inputModel;