Use built-in is_terminal instead of is_terminal::is_terminal (#9550)

# Description
This PR tries to remove ~atty~ is-terminal from the entire code base,
since ~[atty is
unmaintained](https://rustsec.org/advisories/RUSTSEC-2021-0145) and~
[`is_terminal` has been
stabilized](https://blog.rust-lang.org/2023/06/01/Rust-1.70.0.html#isterminal)
in rust 1.70.0.

cc @fdncred 

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crates/nu-cli/src/repl.rs

@@ -6,7 +6,6 @@ use crate::{
     NuHighlighter, NuValidator, NushellPrompt,
 };
 use crossterm::cursor::SetCursorStyle;
-use is_terminal::IsTerminal;
 use log::{trace, warn};
 use miette::{ErrReport, IntoDiagnostic, Result};
 use nu_cmd_base::util::get_guaranteed_cwd;
@@ -26,7 +25,7 @@ use reedline::{
     SqliteBackedHistory, Vi,
 };
 use std::{
-    io::{self, Write},
+    io::{self, IsTerminal, Write},
     path::Path,
     sync::atomic::Ordering,
     time::Instant,