https://github.com/elastic/elasticsearch/pull/97304 removes several places that might do an expensive rebuild of the cluster state via `getStateForMasterService`. There's one other call we should be able to remove, in `JoinValidationService`, but it's a little tricky since we rely on seeing the last-accepted state for the cluster UUID validation, and it's not obviously ok to expose the last-accepted state without the no-master block.

This is a fairly minor issue because we do not do this join validation during elections, only if we're the elected master, and in that case `getStateForMasterService` is cheap. But that's not guaranteed, and we should strengthen this to avoid the that expensive step whenever possible.
server/src/main/java/org/elasticsearch/cluster/coordination/Coordinator.java
Mode getMode() {
        synchronized (mutex) {
            return mode;
        }
    }
    
    DiscoveryNode getLocalNode() {
        return transportService.getLocalNode();
    }
    
    boolean publicationInProgress() {
        synchronized (mutex) {
            return currentPublication.isPresent();
        }
    }
    @Override
    protected void doStart() {
        synchronized (mutex) {
            CoordinationState.PersistedState persistedState = persistedStateSupplier.get();
            coordinationState.set(new CoordinationState(getLocalNode(), persistedState, electionStrategy));
            peerFinder.setCurrentTerm(getCurrentTerm());
            configuredHostsResolver.start();
            final ClusterState lastAcceptedState = coordinationState.get().getLastAcceptedState();
            clusterBootstrapService.logBootstrapState(lastAcceptedState.metadata());
            final VotingConfiguration votingConfiguration = lastAcceptedState.getLastCommittedConfiguration();
            if (singleNodeDiscovery
                && votingConfiguration.isEmpty() == false
                && votingConfiguration.hasQuorum(Collections.singleton(getLocalNode().getId())) == false) {
                throw new IllegalStateException(