Filter out ClientBuilderExtensionsDefinition for MPG (Azure#50971)

Author: live1206

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/ManagementClientGenerator.cs

@@ -53,6 +53,7 @@ protected override void Configure()
             AddVisitor(new ResourceVisitor());
             AddVisitor(new InheritableSystemObjectModelVisitor());
             AddVisitor(new NameVisitor());
+            AddVisitor(new TypeFilterVisiter());
         }
     }
 }

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/TypeFilterVisiter.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using Microsoft.TypeSpec.Generator.ClientModel;
+using Microsoft.TypeSpec.Generator.Providers;
+
+namespace Azure.Generator.Management
+{
+    internal class TypeFilterVisiter : ScmLibraryVisitor
+    {
+        /// <inheritdoc/>
+        protected override TypeProvider? VisitType(TypeProvider type)
+        {
+            // This visitor is used to filter types, so we return null to remove the type from the output.
+            if (type is not null && type.Name.EndsWith("ClientBuilderExtensions"))
+            {
+                return null;
+            }
+            return type;
+        }
+    }
+}