### CI Link

https://gradle-enterprise.elastic.co/s/yckwl5zjomfas

### Repro line

```
./gradlew ':server:test' --tests "org.elasticsearch.cluster.coordination.CoordinatorTests.testSingleNodeDiscoveryStabilisesEvenWhenDisrupted" -Dtests.seed=949AB28501F8ED37:BBC20DD1A5D4EF81
```

### Does it reproduce?

Yes

### Applicable branches

main

### Failure history

https://ci-stats.elastic.co/s/jenkins/goto/da1547f0-2ea6-11ed-8233-4bd40c8511bb - 3 similar-looking failures over the last 90 days

### Failure excerpt

```org.elasticsearch.cluster.coordination.CoordinatorTests > testSingleNodeDiscoveryStabilisesEvenWhenDisrupted FAILED
    java.lang.AssertionError: leaders
    Expected: not an empty collection
         but: was <[]>
        at __randomizedtesting.SeedInfo.seed([949AB28501F8ED37:BBC20DD1A5D4EF81]:0)
        at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:18)
        at org.junit.Assert.assertThat(Assert.java:956)
        at org.elasticsearch.cluster.coordination.AbstractCoordinatorTestCase$Cluster.getAnyLeader(AbstractCoordinatorTestCase.java:791)
        at org.elasticsearch.cluster.coordination.CoordinatorTests.testSingleNodeDiscoveryStabilisesEvenWhenDisrupted(CoordinatorTests.java:1939)


Suite: Test class org.elasticsearch.cluster.coordination.CoordinatorTests
  2> REPRODUCE WITH: ./gradlew ':server:test' --tests "org.elasticsearch.cluster.coordination.CoordinatorTests.testSingleNodeDiscoveryStabilisesEvenWhenDisrupted" -Dtests.seed=949AB28501F8ED37 -Dtests.locale=en-AU -Dtests.timezone=Europe/Vienna -Druntime.java=18
  2> java.lang.AssertionError: leaders
    Expected: not an empty collection
         but: was <[]>
        at __randomizedtesting.SeedInfo.seed([949AB28501F8ED37:BBC20DD1A5D4EF81]:0)
        at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:18)
        at org.junit.Assert.assertThat(Assert.java:956)
        at org.elasticsearch.cluster.coordination.AbstractCoordinatorTestCase$Cluster.getAnyLeader(AbstractCoordinatorTestCase.java:791)
        at org.elasticsearch.cluster.coordination.CoordinatorTests.testSingleNodeDiscoveryStabilisesEvenWhenDisrupted(CoordinatorTests.java:1939)
  2> NOTE: leaving temporary files on disk at: /home/davidturner/src/elasticsearch/server/build/testrun/test/temp/org.elasticsearch.cluster.coordination.CoordinatorTests_949AB28501F8ED37-002
  2> NOTE: test params are: codec=Asserting(Lucene94): {}, docValues:{}, maxPointsInLeafNode=1598, maxMBSortInHeap=6.485414969465074, sim=Asserting(RandomSimilarity(queryNorm=true): {}), locale=en-AU, timezone=Europe/Vienna
  2> NOTE: Linux 5.4.0-125-generic amd64/Oracle Corporation 18.0.2.1 (64-bit)/cpus=8,threads=1,free=465272544,total=536870912
  2> NOTE: All tests run in this JVM: [CoordinatorTests]

Tests with failures:
 - org.elasticsearch.cluster.coordination.CoordinatorTests.testSingleNodeDiscoveryStabilisesEvenWhenDisrupted
```


server/src/main/java/org/elasticsearch/cluster/coordination/Coordinator.java
}
    private void startElectionScheduler() {
        assert electionScheduler == null : electionScheduler;
        if (getLocalNode().isMasterNode() == false) {
            return;
        }
        final TimeValue gracePeriod = TimeValue.ZERO;
        electionScheduler = electionSchedulerFactory.startElectionScheduler(gracePeriod, new Runnable() {
            @Override
            public void run() {
                synchronized (mutex) {
                    if (mode == Mode.CANDIDATE) {
                        final ClusterState lastAcceptedState = coordinationState.get().getLastAcceptedState();
                        if (localNodeMayWinElection(lastAcceptedState) == false) {
                            logger.trace("skip prevoting as local node may not win election: {}", lastAcceptedState.coordinationMetadata());
                            return;
                        }
                        final StatusInfo statusInfo = nodeHealthService.getHealth();
                        if (statusInfo.getStatus() == UNHEALTHY) {
                            logger.debug("skip prevoting as local node is unhealthy: [{}]", statusInfo.getInfo());
                            return;
                        }
                        if (prevotingRound != null) {
                            prevotingRound.close();
                        }
                        prevotingRound = preVoteCollector.start(lastAcceptedState, getDiscoveredNodes());
                    }
                }
            }
            @Override