**How to reproduce**
Clickhouse server 20.13.1.5273
```
CREATE TABLE default.test
(
`key` UInt32,
`ts` DateTime CODEC(DoubleDelta, LZ4),
`db_time` DateTime DEFAULT now() COMMENT 'spout-ignore' CODEC(DoubleDelta, LZ4)
)
ENGINE = MergeTree
PARTITION BY toStartOfTenMinutes(db_time)
ORDER BY (key, ts)
TTL db_time + toIntervalHour(3)
SETTINGS index_granularity = 8192, merge_with_ttl_timeout = 3600, min_rows_for_compact_part = 1000000, min_bytes_for_compact_part = 200000000, in_memory_parts_enable_wal = 0;


INSERT INTO test(key, ts) SELECT number % 1000, now() + intDiv(number,1000) FROM numbers(500);

SELECT * FROM test;
500 rows in set. Elapsed: 0.003 sec.

DETACH TABLE test;

ATTACH TABLE test;

SELECT * FROM test;

0 rows in set. Elapsed: 0.002 sec.
```

**Expected behavior**
Clickhouse would flush parts on disk.
ContextPtr local_context, PartsTemporaryRename & renamed_parts)
{
    const String source_dir = "detached/";
    std::map<String, DiskPtr> name_to_disk;
    /
    if (attach_part)
    {
        const String part_id = partition->as<ASTLiteral &>().value.safeGet<String>();
        validateDetachedPartName(part_id);
        auto disk = getDiskForDetachedPart(part_id);
        renamed_parts.addPart(part_id, "attaching_" + part_id, disk);
        if (MergeTreePartInfo::tryParsePartName(part_id, format_version))
            name_to_disk[part_id] = getDiskForDetachedPart(part_id);
    }
    else
    {
        String partition_id = getPartitionIDFromQuery(partition, local_context);
        LOG_DEBUG(log, "Looking for parts for partition {} in {}", partition_id, source_dir);
        ActiveDataPartSet active_parts(format_version);
        auto detached_parts = getDetachedParts();
        auto new_end_it = std::remove_if(detached_parts.begin(), detached_parts.end(), [&partition_id](const DetachedPartInfo & part_info)
        {
            return !part_info.valid_name || !part_info.prefix.empty() || part_info.partition_id != partition_id;
        });