**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.
{
    LOG_DEBUG(log, "Loading data parts");
    auto metadata_snapshot = getInMemoryMetadataPtr();
    const auto settings = getSettings();
    MutableDataPartsVector parts_from_wal;
    Strings part_file_names;
    auto disks = getStoragePolicy()->getDisks();
    
    if (!getStoragePolicy()->isDefaultPolicy() && !skip_sanity_checks)
    {
        
        std::unordered_set<String> defined_disk_names;
        for (const auto & disk_ptr : disks)
            defined_disk_names.insert(disk_ptr->getName());
        for (const auto & [disk_name, disk] : getContext()->getDisksMap())
        {
            if (defined_disk_names.count(disk_name) == 0 && disk->exists(relative_data_path))
            {
                for (const auto it = disk->iterateDirectory(relative_data_path); it->isValid(); it->next())
                {
                    if (MergeTreePartInfo::tryParsePartName(it->name(), format_version))
                        throw Exception(ErrorCodes::UNKNOWN_DISK,
                            "Part {} was found on disk {} which is not defined in the storage policy",
                            backQuote(it->name()), backQuote(disk_name));
                }