Fix Flaky Test SearchWithRandomExceptionsIT.testRandomExceptions

Signed-off-by: kkewwei <kewei.11@bytedance.com>
Signed-off-by: kkewwei <kkewwei@163.com>

server/src/internalClusterTest/java/org/opensearch/search/basic/SearchWithRandomExceptionsIT.java

@@ -193,6 +193,11 @@ public void testRandomExceptions() throws IOException, InterruptedException, Exe
                 logger.info("expected SearchPhaseException: [{}]", ex.getMessage());
             }
         }
+
+        // as the index refresh may fail, so the translog in the index will be not flushed,
+        // and `TranslogWriter.buffer` is not null, which causes arrays not been released,
+        // so we need to close the index to release the arrays.
+        cluster().wipeIndices("test");
     }
 
     public static final String EXCEPTION_TOP_LEVEL_RATIO_KEY = "index.engine.exception.ratio.top";