**Describe the bug**
For DATABASE ENGINE Atomic (used by Default for all databases from 20.10) 
when try to `DROP TALBE replicatedmergetree table ON CLUSTER ... SYNC`, query failed after `distributed_ddl_task_timeout` seconds
`decrease `database_atomic_delay_before_drop_table_sec=1` and setup `database_atomic_wait_for_drop_and_detach_synchronously=1` for default user profile didn't help

**How to reproduce**
just look to https://gist.github.com/Slach/a7f2946a108883f6b1d5585b1b5b6b0d
```
bash -x ./reproduce.sh
```

* Which ClickHouse server version to use
Latest official docker build

* Non-default settings, if any
```
<yandex>
    <database_atomic_delay_before_drop_table_sec>1</database_atomic_delay_before_drop_table_sec>
    <profile>
        <default>
            <database_atomic_wait_for_drop_and_detach_synchronously>1</database_atomic_wait_for_drop_and_detach_synchronously>
            <distributed_ddl_task_timeout>20</distributed_ddl_task_timeout>
        </default>
    </profile>
</yandex>

```

**Expected behavior**
Successfull DROP TABLE on cluster

**Error message and/or stacktrace**
Code: 159. DB::Exception: Received from localhost:9000. DB::Exception: Watching task /clickhouse/task_queue/ddl/query-0000000001 is executing longer than distributed_ddl_task_timeout (=20) seconds. There are 2 unfinished hosts (0 of them are currently active), they are going to execute the query in background.

**Additional context**
table physically deleted, but Atomic engine doesn't return "finished" flag to Zookeeper `distributed_ddl` queue

```
docker-compose exec clickhouse-0-0-0 clickhouse-client -q "SELECT * FROM system.zookeeper WHERE path='/clickhouse/task_queue/ddl/query-0000000001/finished' FORMAT
Vertical"
```

returns empty result


: context(context_)
    , log(&Poco::Logger::get("DDLWorker"))
    , pool_size(pool_size_)
    , worker_pool(std::make_unique<ThreadPool>(pool_size))
{
    CurrentMetrics::set(CurrentMetrics::MaxDDLEntryID, 0);
    last_tasks.reserve(pool_size);
    queue_dir = zk_root_dir;
    if (queue_dir.back() == '/')
        queue_dir.resize(queue_dir.size() - 1);
    if (config)
    {
        task_max_lifetime = config->getUInt64(prefix + ".task_max_lifetime", static_cast<UInt64>(task_max_lifetime));
        cleanup_delay_period = config->getUInt64(prefix + ".cleanup_delay_period", static_cast<UInt64>(cleanup_delay_period));
        max_tasks_in_queue = std::max<UInt64>(1, config->getUInt64(prefix + ".max_tasks_in_queue", max_tasks_in_queue));
        if (config->has(prefix + ".profile"))
            context.setSetting("profile", config->getString(prefix + ".profile"));
    }
    if (context.getSettingsRef().readonly)
    {
        LOG_WARNING(log, "Distributed DDL worker is run with readonly settings, it will not be able to execute DDL queries Set appropriate system_profile or distributed_ddl.profile to fix this.");
    }
    host_fqdn = getFQDNOrHostName();
    host_fqdn_id = Cluster::Address::toString(host_fqdn, context.getTCPPort());
    main_thread = ThreadFromGlobalPool(&DDLWorker::runMainThread, this);
    cleanup_thread = ThreadFromGlobalPool(&DDLWorker::runCleanupThread, this);
}
DDLWorker::~DDLWorker()