Remove undo/redo code from UE Wingman

Plugins/UEWingman/Source/UEWingman/Private/WingServer.cpp

@@ -323,6 +323,9 @@ void UWingServer::TryCallHandler(const FString &Line)
 		return;
 	}
 
+	// MCP handlers must not run inside an undo transaction.
+	check(GUndo == nullptr);
+
 	// Invoke the handler.
 	Handler->Handle();
 }