**Build scan:**
https://gradle-enterprise.elastic.co/s/bcxstpjolnb2q/tests/:x-pack:plugin:ccr:internalClusterTest/org.elasticsearch.xpack.ccr.FollowerFailOverIT/testReadRequestsReturnLatestMappingVersion

**Reproduction line:**
```
./gradlew ':x-pack:plugin:ccr:internalClusterTest' --tests "org.elasticsearch.xpack.ccr.FollowerFailOverIT.testReadRequestsReturnLatestMappingVersion" -Dtests.seed=A75C1F0C6F541957 -Dtests.locale=fr-CA -Dtests.timezone=America/Tijuana -Druntime.java=20
```

**Applicable branches:**
8.10

**Reproduces locally?:**
Didn't try

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.xpack.ccr.FollowerFailOverIT&tests.test=testReadRequestsReturnLatestMappingVersion

**Failure excerpt:**
```
com.carrotsearch.randomizedtesting.UncaughtExceptionError: Captured an uncaught exception in thread: Thread[id=498, name=elasticsearch[follower2][clusterApplierService#updateTask][T#1], state=RUNNABLE, group=TGRP-FollowerFailOverIT]

  at __randomizedtesting.SeedInfo.seed([A75C1F0C6F541957:A564CB31A58082CC]:0)

  Caused by: java.lang.AssertionError: (No message provided)

    at __randomizedtesting.SeedInfo.seed([A75C1F0C6F541957]:0)
    at org.elasticsearch.discovery.PeerFinder.closePeers(PeerFinder.java:182)
    at org.elasticsearch.cluster.coordination.Coordinator.onClusterStateApplied(Coordinator.java:415)
    at org.elasticsearch.cluster.coordination.Coordinator.lambda$handleApplyCommit$8(Coordinator.java:403)
    at org.elasticsearch.action.ActionListenerImplementations$MappedActionListener.lambda$map$0(ActionListenerImplementations.java:108)
    at org.elasticsearch.action.ActionListenerImplementations$MappedActionListener.onResponse(ActionListenerImplementations.java:89)
    at org.elasticsearch.cluster.service.ClusterApplierService$ClusterApplyActionListener.onResponse(ClusterApplierService.java:598)
    at org.elasticsearch.cluster.service.ClusterApplierService$ClusterApplyActionListener.onResponse(ClusterApplierService.java:569)
    at org.elasticsearch.cluster.service.ClusterApplierService.runTask(ClusterApplierService.java:439)
    at org.elasticsearch.cluster.service.ClusterApplierService$UpdateTask.run(ClusterApplierService.java:154)
    at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingRunnable.run(ThreadContext.java:916)
    at org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.runAndClean(PrioritizedEsThreadPoolExecutor.java:217)
    at org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.run(PrioritizedEsThreadPoolExecutor.java:183)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
    at java.lang.Thread.run(Thread.java:1623)

```
server/src/main/java/org/elasticsearch/cluster/coordination/Coordinator.java
}
            }
        };
    }
    private void cancelActivePublication(String reason) {
        assert Thread.holdsLock(mutex) : "Coordinator mutex not held";
        if (currentPublication.isPresent()) {
            currentPublication.get().cancel(reason);
        }
    }
    public Collection<BiConsumer<DiscoveryNode, ClusterState>> getOnJoinValidators() {
        return onJoinValidators;
    }
    
    boolean hasIdleJoinValidationService() {
        return joinValidationService.isIdle();
    }
    
    boolean electionSchedulerActive() {
        return electionScheduler != null;
    }
    public void addPeerFinderListener(PeerFinderListener peerFinderListener) {
        this.peerFinderListeners.add(peerFinderListener);
    }
    public enum Mode {
        CANDIDATE,
        LEADER,
        FOLLOWER
    }
    private class CoordinatorPeerFinder extends PeerFinder {