fix: Compilation error missing use JsonLineReader (#19244)

Co-authored-by: sunadase <[email protected]>

crates/polars-mem-engine/src/executors/scan/ndjson.rs

@@ -1,5 +1,6 @@
 use polars_core::config;
 use polars_core::utils::accumulate_dataframes_vertical;
+use polars_io::prelude::{JsonLineReader, SerReader};
 use polars_io::utils::compression::maybe_decompress_bytes;
 
 use super::*;