fix test cases for nesting mode

Author: zhongkechen

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

@@ -1151,6 +1151,7 @@ void testParallelWithFirstSuccessful_earlyTermination(NestingType nestingType, i
 
         var result = runner.runUntilComplete("test");
         assertEquals(ExecutionStatus.SUCCEEDED, result.getStatus());
-        assertEquals(events, result.getHistoryEvents().size());
+        // might be fewer if some branches are cancelled before completion
+        assertTrue(result.getHistoryEvents().size() <= events);
     }
 }