[I] [C++] Fix ASAN issue in the arrow-dataset-dataset-writer-test [arrow]

wgtmac opened a new issue, #45235: URL: https://github.com/apache/arrow/issues/45235 ### Describe the bug, including details regarding any error messages, version, and platform. https://github.com/apache/arrow/actions/runs/12739705161/job/35503788331?pr=45226 ``` ==

[I] [Java][FlightSQL] Inconsistent GET_PRIMARY_KEYS_SCHEMA [arrow]

devinrsmith opened a new issue, #45233: URL: https://github.com/apache/arrow/issues/45233 ### Describe the bug, including details regarding any error messages, version, and platform. The protobuf documentation [^1] for the returned schema of FlightSQL CommandGetPrimaryKeys is