[Chore] Use defer to close rows in examples

[hayotbisonai]

Summary

• Updated row.Close() to defer rows.Close()
• It ensures that row resources are consistently released, even if an error occurs during further processing in the function. Using defer to close resources improves code reliability and readability.

Checklist

Delete items not relevant to your PR:

• Unit and integration tests covering the common scenarios were added
• A human-readable description of the changes was provided to include in CHANGELOG
• For significant changes, documentation in https://github.com/ClickHouse/clickhouse-docs was updated with further explanations or tutorials