IGNITE-26861 Fixed flaky IgniteCacheClientNodeChangingTopologyTest.testPessimisticTxNearEnabled (#12478)

Author: petrov-mg

modules/core/src/test/java/org/apache/ignite/internal/processors/cache/distributed/IgniteCacheClientNodeChangingTopologyTest.java

@@ -573,6 +573,8 @@ private void pessimisticTx(NearCacheConfiguration nearCfg) throws Exception {
 
         ignite3.close();
 
+        awaitPartitionMapExchange();
+
         for (int i = 0; i < 100; i++)
             map.put(i, i + 1);
 
@@ -596,14 +598,14 @@ private void pessimisticTx(NearCacheConfiguration nearCfg) throws Exception {
 
         startGrid(3);
 
+        awaitPartitionMapExchange();
+
         log.info("Stop block2.");
 
         spi.stopBlock();
 
         putFut.get();
 
-        awaitPartitionMapExchange();
-
         checkData(map, null, cache, 4);
 
         for (int i = 0; i < 100; i++)