Apache Airflow Samba provider: Path traversal in GCSToSambaOperator via GCS object names

The Apache Airflow Samba provider's `GCSToSambaOperator` joined GCS object names to the SMB destination path without a containment check, so an object named with `../` segments resolved a write path outside the configured `destination_path`. An attacker able to write objects into the source GCS bucket — typically an external data producer distinct from the trusted DAG author — could write files to arbitrary locations on the Samba target when the operator ran. Upgrade apache-airflow-providers-samba to 4.12.6 or later, which validates the resolved destination stays within `destination_path`.