**Build scan:**
https://gradle-enterprise.elastic.co/s/lnrkom7tlgmgc/tests/:server:test/org.elasticsearch.action.search.SearchResponseTests/testSerialization

**Reproduction line:**
```
./gradlew ':server:test' --tests "org.elasticsearch.action.search.SearchResponseTests.testSerialization" -Dtests.seed=E3EE3D74ECB7F477 -Dtests.locale=en-PH -Dtests.timezone=America/Bahia_Banderas -Druntime.java=21
```

**Applicable branches:**
main

**Reproduces locally?:**
Yes

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.action.search.SearchResponseTests&tests.test=testSerialization

**Failure excerpt:**
```
java.lang.AssertionError: expected: org.elasticsearch.action.search.SearchResponse$Clusters<Clusters{total=3, successful=2, skipped=1, running=0, partial=0, failed=0}> but was: org.elasticsearch.action.search.SearchResponse$Clusters<Clusters{total=3, successful=2, skipped=1, running=0, partial=0, failed=0}>

  at __randomizedtesting.SeedInfo.seed([E3EE3D74ECB7F477:B7365C3CCBE5C9EB]:0)
  at org.junit.Assert.fail(Assert.java:88)
  at org.junit.Assert.failNotEquals(Assert.java:834)
  at org.junit.Assert.assertEquals(Assert.java:118)
  at org.junit.Assert.assertEquals(Assert.java:144)
  at org.elasticsearch.action.search.SearchResponseTests.testSerialization(SearchResponseTests.java:612)
  at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
  at java.lang.reflect.Method.invoke(Method.java:580)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.invoke(RandomizedRunner.java:1758)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$8.evaluate(RandomizedRunner.java:946)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$9.evaluate(RandomizedRunner.java:982)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$10.evaluate(RandomizedRunner.java:996)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleSetupTeardownChained$1.evaluate(TestRuleSetupTeardownChained.java:48)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleThreadAndTestName$1.evaluate(TestRuleThreadAndTestName.java:45)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.forkTimeoutingTask(ThreadLeakControl.java:843)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$3.evaluate(ThreadLeakControl.java:490)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.runSingleTest(RandomizedRunner.java:955)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$5.evaluate(RandomizedRunner.java:840)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$6.evaluate(RandomizedRunner.java:891)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$7.evaluate(RandomizedRunner.java:902)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleStoreClassName$1.evaluate(TestRuleStoreClassName.java:38)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleAssertionsRequired$1.evaluate(TestRuleAssertionsRequired.java:53)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleIgnoreTestSuites$1.evaluate(TestRuleIgnoreTestSuites.java:47)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.lambda$forkTimeoutingTask$0(ThreadLeakControl.java:850)
  at java.lang.Thread.run(Thread.java:1583)

```
server/src/main/java/org/elasticsearch/action/search/SearchResponse.java
+ successful
                    + " skipped: "
                    + skipped
                    + " running: "
                    + running
                    + " partial: "
                    + partial
                    + " failed: "
                    + failed;
        }
        private Clusters(Map<String, AtomicReference<Cluster>> clusterInfoMap) {
            assert clusterInfoMap.size() > 0 : "this constructor should not be called with an empty Cluster info map";
            this.total = clusterInfoMap.size();
            this.clusterInfo = clusterInfoMap;
            this.successful = 0;    
            this.skipped = 0;       
            this.running = 0;       
            this.partial = 0;       
            this.failed = 0;        
            
            this.ccsMinimizeRoundtrips = true;
        }
        @Override
        public void writeTo(StreamOutput out) throws IOException {
            out.writeVInt(total);
            out.writeVInt(successful);
            out.writeVInt(skipped);
            if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_500_053)) {
                if (clusterInfo != null) {
                    List<Cluster> clusterList = clusterInfo.values().stream().map(AtomicReference::get).toList();