fix: Don't encode IPC record batch twice (#21525)

crates/polars-arrow/src/io/ipc/write/writer.rs

@@ -7,7 +7,7 @@ use polars_error::{polars_bail, PolarsResult};
 use super::super::{IpcField, ARROW_MAGIC_V2};
 use super::common::{DictionaryTracker, EncodedData, WriteOptions};
 use super::common_sync::{write_continuation, write_message};
-use super::{default_ipc_fields, encode_record_batch, schema, schema_to_bytes};
+use super::{default_ipc_fields, schema, schema_to_bytes};
 use crate::array::Array;
 use crate::datatypes::*;
 use crate::io::ipc::write::common::encode_chunk_amortized;
@@ -159,7 +159,6 @@ impl<W: Write> FileWriter<W> {
             &self.options,
             &mut self.encoded_message,
         )?;
-        encode_record_batch(chunk, &self.options, &mut self.encoded_message);
 
         let encoded_message = std::mem::take(&mut self.encoded_message);
         self.write_encoded(&encoded_dictionaries[..], &encoded_message)?;