Function write_parquet_position_delete_file 

pub async fn write_parquet_position_delete_file(
    table: &Table,
    location_generator: &DefaultLocationGenerator,
    file_name_generator: &DefaultFileNameGenerator,
    config: &IcebergConfig,
    data_file_path: String,
    delete_vector: &DeleteVector,
    partition_key: Option<&PartitionKey>,
) -> Result<DataFile>

Writes delete_vector as a single file-scoped Parquet position-delete file referencing data_file_path, and returns its [DataFile] metadata (content PositionDeletes, format Parquet) with referenced_data_file set.