For some reasons when we delete a MergeTree Part in atomic way something may go wrong - and leave the `delete_tmp_*` folder or it's part on disk. This may lead to a disk space consumption over time.

It's suggested to delete this folders at least at server start-up. Current solution with `clearOldTemporaryDirectories()` doesn't work because this method is called periodically from a thread without any locks or advisory on folders - it may cause the race conditions.
{
    LOG_TRACE(log, "Killing mutation {}", mutation_id);
    UInt64 mutation_version = MergeTreeMutationEntry::tryParseFileName(mutation_id);
    if (!mutation_version)
        return CancellationCode::NotFound;
    std::optional<MergeTreeMutationEntry> to_kill;
    {
        std::lock_guard lock(currently_processing_in_background_mutex);
        auto it = current_mutations_by_version.find(mutation_version);
        if (it != current_mutations_by_version.end())
        {
            to_kill.emplace(std::move(it->second));
            current_mutations_by_version.erase(it);
        }
    }
    if (!to_kill)
        return CancellationCode::NotFound;
    if (auto txn = tryGetTransactionForMutation(*to_kill, log))
    {
        LOG_TRACE(log, "Cancelling transaction {} which had started mutation {}", to_kill->tid, mutation_id);
        TransactionLog::instance().rollbackTransaction(txn);
    }
    getContext()->getMergeList().cancelPartMutations(getStorageID(), {}, to_kill->block_number);
    to_kill->removeFile();