**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.
{
            auto & column = assert_cast<ColumnAggregateFunction &>(*partition_minmax_count_columns.back());
            auto func = column.getAggregateFunction();
            Arena & arena = column.createOrGetArena();
            size_t size_of_state = func->sizeOfData();
            size_t align_of_state = func->alignOfData();
            auto * place = arena.alignedAlloc(size_of_state, align_of_state);
            func->create(place);
            const AggregateFunctionCount & agg_count = assert_cast<const AggregateFunctionCount &>(*func);
            agg_count.set(place, part->rows_count);
            column.insertFrom(place);
        }
    }
    block.setColumns(std::move(partition_minmax_count_columns));
    Block res;
    for (const auto & name : required_columns)
    {
        if (virtual_columns_block.has(name))
            res.insert(virtual_columns_block.getByName(name));
        else if (block.has(name))
            res.insert(block.getByName(name));
        else
            throw Exception(
                ErrorCodes::LOGICAL_ERROR,
                "Cannot find column {} in minmax_count projection but query analysis still selects this projection. It's a bug",
                name);
    }
    return res;
}
std::optional<ProjectionCandidate> MergeTreeData::getQueryProcessingStageWithAggregateProjection(