Refactor error handling imports in dataframe.rs for improved clarity and consistency

Author: kosiew

src/dataframe.rs

@@ -42,11 +42,10 @@ use pyo3::exceptions::PyValueError;
 use pyo3::prelude::*;
 use pyo3::pybacked::PyBackedStr;
 use pyo3::types::{PyCapsule, PyList, PyTuple, PyTupleMethods};
-use tokio::task::JoinHandle;
 use tokio::time::{sleep, Duration};
 
 use crate::catalog::PyTable;
-use crate::errors::{py_datafusion_err, PyDataFusionError};
+use crate::errors::{py_datafusion_err, to_datafusion_err, PyDataFusionError};
 use crate::expr::sort_expr::to_sort_expressions;
 use crate::physical_plan::PyExecutionPlan;
 use crate::record_batch::PyRecordBatchStream;