cli: use is_tty() from crossterm crate instead of atty

The `atty` crate seems unmaintained. There's
https://rustsec.org/advisories/RUSTSEC-2021-0145 filed against it,
which `cargo-deny` complains about. A fix for that has been open for
well over a year without being fixed
(softprops/atty#51). It turns out the
functionality is also available via the `crossterm` crate (thanks,
@yuja), which we already depend on.

Since we also depend on `atty` via `clap`, I also added an exception
to the `cargo-deny` config.

Cargo.toml

@@ -34,7 +34,6 @@ harness = false
 members = ["lib"]
 
 [dependencies]
-atty = "0.2.14"
 chrono = { version = "0.4.23", default-features = false, features = ["std", "clock"] }
 clap = { version = "4.0.26", features = ["derive", "deprecated"] }
 clap_complete = "4.0.5"

deny.toml

@@ -51,6 +51,7 @@ notice = "warn"
 # output a note when they are encountered.
 ignore = [
     #"RUSTSEC-0000-0000",
+    "RUSTSEC-2021-0145",
 ]
 # Threshold for security vulnerabilities, any vulnerability with a CVSS score
 # lower than the range specified will be ignored. Note that ignored advisories

src/ui.rs

@@ -17,7 +17,7 @@ use std::path::{Path, PathBuf};
 use std::str::FromStr;
 use std::{fmt, io};
 
-use atty::Stream;
+use crossterm::tty::IsTty;
 use jujutsu_lib::settings::UserSettings;
 
 use crate::formatter::{Formatter, FormatterFactory};
@@ -80,7 +80,7 @@ fn use_color(choice: ColorChoice) -> bool {
     match choice {
         ColorChoice::Always => true,
         ColorChoice::Never => false,
-        ColorChoice::Auto => atty::is(Stream::Stdout),
+        ColorChoice::Auto => io::stdout().is_tty(),
     }
 }
 
@@ -154,7 +154,7 @@ impl Ui {
     /// Whether continuous feedback should be displayed for long-running
     /// operations
     pub fn use_progress_indicator(&self) -> bool {
-        self.settings().use_progress_indicator() && atty::is(Stream::Stdout)
+        self.settings().use_progress_indicator() && io::stdout().is_tty()
     }
 
     pub fn write(&mut self, text: &str) -> io::Result<()> {
@@ -208,7 +208,7 @@ impl Ui {
     }
 
     pub fn prompt(&mut self, prompt: &str) -> io::Result<String> {
-        if !atty::is(Stream::Stdout) {
+        if !io::stdout().is_tty() {
             return Err(io::Error::new(
                 io::ErrorKind::Unsupported,
                 "Cannot prompt for input since the output is not connected to a terminal",
@@ -222,7 +222,7 @@ impl Ui {
     }
 
     pub fn prompt_password(&mut self, prompt: &str) -> io::Result<String> {
-        if !atty::is(Stream::Stdout) {
+        if !io::stdout().is_tty() {
             return Err(io::Error::new(
                 io::ErrorKind::Unsupported,
                 "Cannot prompt for input since the output is not connected to a terminal",