Hello,

so I'm working to integrate CatBoost model with our ClickHouse cluster. It appears that, whenever we create a new XML model file in the configured path, the **first** call to the new model never returns (this is true both of the HTTP interface as well as via clickhouse-client).

Independently from whether the locked statement gets cancelled, subsequent calls succeed immediately.

```
16e8bdb5bbb9 :) select version();

SELECT version()

┌─version()─┐
│ 20.6.3.28 │
└───────────┘

1 rows in set. Elapsed: 0.006 sec.
```

Is this known behavior? If it helps, my models look like this:

```
<models>
    <model>
        <type>catboost</type>
        <name>ctr_predictor</name>
        <path>/catboost/my_predictor</path>
        <lifetime>0</lifetime>
    </model>
</models>
```
{
        auto it = infos.find(name);
        if (it == infos.end())
            return nullptr;
        return &it->second;
    }
    template <typename ReturnType>
    ReturnType collectLoadResults(const FilterByNameFunction & filter) const
    {
        ReturnType results;
        results.reserve(infos.size());
        for (const auto & [name, info] : infos)
        {
            if (!filter || filter(name))
            {
                auto result = info.template getLoadResult<typename ReturnType::value_type>();
                if constexpr (std::is_same_v<typename ReturnType::value_type, LoadablePtr>)
                {
                    if (!result)
                        continue;
                }
                results.emplace_back(std::move(result));
            }
        }
        return results;
    }
    Info * loadImpl(const String & name, Duration timeout, bool forced_to_reload, std::unique_lock<std::mutex> & lock)