Looks like https://github.com/ClickHouse/ClickHouse/pull/21303 is broke also "clear column" for such columns.

How to reproduce:

```
CREATE TABLE test.TTAdmLog
(
    `ts` DateTime,
    `event_date` Date DEFAULT toDate(ts),
    `impression_id` String DEFAULT '',
    `creative_id` String DEFAULT '',
    `creative_adm` String DEFAULT '',
    `impression_id_compressed` FixedString(16) DEFAULT UUIDStringToNum(impression_id),
    `impression_id_hashed` UInt16 DEFAULT reinterpretAsUInt16(impression_id_compressed),
)
ENGINE = ReplicatedMergeTree('/clickhouse/tables/{shard}/TTAdmLogTest', '{replica}')
PARTITION BY toMonday(event_date)
ORDER BY (event_date, impression_id_hashed)
SAMPLE BY impression_id_hashed
SETTINGS replicated_deduplication_window = 1000, replicated_deduplication_window_seconds = 864000, index_granularity = 8192

CREATE MATERIALIZED VIEW test.TTView
(
    `event_date` Date,
    `creative_id` String,
    `creative_adm` AggregateFunction(anyLast, String),
)
ENGINE = ReplicatedAggregatingMergeTree('/clickhouse/tables/{shard}/TTViewTest', '{replica}', event_date, (event_date, creative_id), 8192) AS
SELECT 
    toStartOfMonth(event_date) AS event_date,
    arrayJoin(splitByChar(',', creative_id)) AS creative_id,
    anyLastState(creative_adm) AS creative_adm,
FROM test.TTAdmLog
GROUP BY 
    event_date,
    creative_id,

```


ClickHouse server version 20.9.3 revision 54439.

```
alter table test.TTAdmLog clear column creative_adm in partition '2021-03-22'

OK

```
ClickHouse server version 21.4.3 revision 54447.

```
alter table test.TTAdmLog  clear column creative_adm in partition '2021-03-22'

DB::Exception: Trying to ALTER DROP column creative_adm which is referenced by materialized view ['TTView'].

```

return;
        }
        
        const auto start_shard_num = getThreadId() % storage.num_shards;
        
        auto shard_num = start_shard_num;
        StorageBuffer::Buffer * least_busy_buffer = nullptr;
        std::unique_lock<std::mutex> least_busy_lock;
        size_t least_busy_shard_rows = 0;
        for (size_t try_no = 0; try_no < storage.num_shards; ++try_no)
        {
            std::unique_lock lock(storage.buffers[shard_num].tryLock());
            if (lock.owns_lock())
            {
                size_t num_rows = storage.buffers[shard_num].data.rows();
                if (!least_busy_buffer || num_rows < least_busy_shard_rows)
                {
                    least_busy_buffer = &storage.buffers[shard_num];
                    least_busy_lock = std::move(lock);
                    least_busy_shard_rows = num_rows;
                }
            }
            shard_num = (shard_num + 1) % storage.num_shards;
        }
        
        if (!least_busy_buffer)
        {
            least_busy_buffer = &storage.buffers[start_shard_num];
            least_busy_lock = least_busy_buffer->lockForWriting();
        }