remove unnecessary code in example

Author: rose-a

examples/GraphQL.Client.Example/Program.cs

@@ -10,7 +10,6 @@ public class Program {
 
 		public static async Task Main(string[] args) {
 
-			var serializer = new NewtonsoftJsonSerializer();
 			using var graphQLClient = new GraphQLHttpClient("https://swapi.apis.guru/");
 
 			var personAndFilmsRequest = new GraphQLRequest {