fixed compiler warnings

src/readline/history.rs

@@ -472,7 +472,7 @@ mod tests {
   use super::*;
   use crate::{state, testutil::TestGuard};
   use scopeguard::guard;
-  use std::{env, fs, path::Path, sync::Mutex};
+  use std::{env, fs, path::Path};
   use tempfile::tempdir;
 
   fn with_env_var(key: &str, val: &str) -> impl Drop {

src/readline/term.rs

@@ -4,7 +4,7 @@ use std::{
   fmt::{Debug, Write},
   io::{BufRead, BufReader, Read},
   os::fd::{AsFd, BorrowedFd, RawFd},
-  sync::Arc, time::Instant,
+  time::Instant,
 };
 
 use nix::{