**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.
for (auto it = begin_it; it != end_it; ++it)
            {
                const PartVersionWithName needle{static_cast<Int64>(it->first), ""};
                auto versions_it = std::lower_bound(
                    part_versions_with_names.begin(), part_versions_with_names.end(), needle);
                if (versions_it != part_versions_with_names.begin())
                {
                    done_count = std::distance(begin_it, it);
                    break;
                }
            }
            if (done_count <= settings->finished_mutations_to_keep)
                return 0;
            to_delete_count = done_count - settings->finished_mutations_to_keep;
        }
        auto it = begin_it;
        for (size_t i = 0; i < to_delete_count; ++i)
        {
            mutations_to_delete.push_back(std::move(it->second));
            it = current_mutations_by_version.erase(it);
        }
    }
    for (auto & mutation : mutations_to_delete)
    {
        LOG_TRACE(log, "Removing mutation: {}", mutation.file_name);
        mutation.removeFile();
    }
    return mutations_to_delete.size();
}
std::vector<StorageMergeTree::PartVersionWithName> StorageMergeTree::getSortedPartVersionsWithNames(