**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
*
     * @param votingConfiguration The nodes that should form the initial configuration.
     * @return whether this call successfully set the initial configuration - if false, the cluster has already been bootstrapped.
     */
    public boolean setInitialConfiguration(final VotingConfiguration votingConfiguration) {
        synchronized (mutex) {
            final ClusterState currentState = getStateForMasterService();
            if (isInitialConfigurationSet()) {
                logger.debug("initial configuration already set, ignoring {}", votingConfiguration);
                return false;
            }
            if (getLocalNode().isMasterNode() == false) {
                logger.debug("skip setting initial configuration as local node is not a master-eligible node");
                throw new CoordinationStateRejectedException(
                    "this node is not master-eligible, but cluster bootstrapping can only happen on a master-eligible node"
                );
            }
            if (votingConfiguration.getNodeIds().contains(getLocalNode().getId()) == false) {
                logger.debug("skip setting initial configuration as local node is not part of initial configuration");
                throw new CoordinationStateRejectedException("local node is not part of initial configuration");
            }
            final List<DiscoveryNode> knownNodes = new ArrayList<>();
            knownNodes.add(getLocalNode());
            peerFinder.getFoundPeers().forEach(knownNodes::add);
            if (votingConfiguration.hasQuorum(knownNodes.stream().map(DiscoveryNode::getId).toList()) == false) {
                logger.debug(
                    "skip setting initial configuration as not enough nodes discovered to form a quorum in the "
                        + "initial configuration [knownNodes={}, {}]",
                    knownNodes,
                    votingConfiguration