fix the test case

Author: zhongkechen

sdk-integration-tests/src/test/java/software/amazon/lambda/durable/ParallelIntegrationTest.java

@@ -1044,7 +1044,7 @@ void testParallelWithFirstSuccessful_earlyTermination() {
             var config = ParallelConfig.builder()
                     .completionConfig(CompletionConfig.firstSuccessful())
                     .build();
-            var parallel = context.parallel("first-successful", config);
+            ParallelDurableFuture parallel = context.parallel("first-successful", config);
 
             try (parallel) {
                 for (var item : List.of("a", "b", "c")) {