Don't trigger CURRENT_WRITE_BUFFER_IS_EXHAUSTED for normal behavior

Why it matters

This change prevents unnecessary exceptions from being raised due to the exhaustion of the current write buffer, which can occur as part of normal system behavior. It improves stability and reduces erroneous error handling in write-intensive workloads.

How to use it

This feature is applied automatically in ClickHouse versions that include this update. There is no configuration required from the user side.