refactor: remove unused ToPyArrow import from dataframe.rs

Author: kosiew

src/dataframe.rs

@@ -26,7 +26,7 @@ use arrow::ffi::FFI_ArrowSchema;
 use arrow::ffi_stream::FFI_ArrowArrayStream;
 use arrow::pyarrow::FromPyArrow;
 use datafusion::arrow::datatypes::{Schema, SchemaRef};
-use datafusion::arrow::pyarrow::{IntoPyArrow, PyArrowType, ToPyArrow};
+use datafusion::arrow::pyarrow::{IntoPyArrow, PyArrowType};
 use datafusion::arrow::util::pretty;
 use datafusion::common::UnnestOptions;
 use datafusion::config::{CsvOptions, ParquetColumnOptions, ParquetOptions, TableParquetOptions};