fix: Fix missing Write trait and unused imports

src/compression_engine/lz4.rs

@@ -1,8 +1,6 @@
 use anyhow::Result;
 use log::*;
-use std::fs::File;
-use std::io::{Read, Write};
-use std::path::PathBuf;
+use std::io::Write;
 
 use lz4_flex::frame::{FrameDecoder, FrameEncoder};