v.25.12Improvement

Add error message that the part was

Add error message that the part was deduplicated. #80264 (Aleksandr Musorin).
Added an explicit error message indicating when a data part was deduplicated during merges or inserts.

Why it matters

This feature improves user visibility and debugging by clearly notifying when a part has been deduplicated, helping users understand the internal deduplication process and ensuring data consistency.

How to use it

No special configuration is required. The error message will automatically appear in logs or query outputs when a part is deduplicated in relevant operations.