Fix HTTP module for latest Spring Framework

spring-integration-http/src/test/java/org/springframework/integration/http/outbound/CookieTests.java

@@ -24,6 +24,7 @@ import java.io.OutputStream;
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 
 import org.junit.jupiter.api.Test;
 
@@ -109,6 +110,11 @@ public class CookieTests {
 					return null;
 				}
 
+				@Override
+				public Map<String, Object> getAttributes() {
+					return null;
+				}
+
 				public ClientHttpResponse execute() {
 					allHeaders.add(headers);
 					MockClientHttpResponse clientHttpResponse =