[coverage] Conformance findings: STATEMENT-023

[peco-engineer-bot]

Surfaced by the multi-language coverage fan-out while conformance-testing these SPEC-IDs against databricks/databricks-sql-go.

Each is committed as an expected-failure (xfail) test in the coverage PR — the test asserts the CORRECT behavior and stays red until this driver is fixed.

• STATEMENT-023: ExecuteUpdate returns 0 for DDL affected-row counts (CREATE/DROP TABLE) instead of the ADBC -1 convention (PECO-3012); DML counts are correct.

Reference driver PR: adbc-drivers/databricks#427
Coverage PR (reproducing xfail tests): https://github.com/databricks/databricks-driver-test/pull/869