atty is unmaintained

[iliana]

GHSA-g98v-hv3f-hcfr

This appears to be the only use:

crucible/common/src/lib.rs

Lines 381 to 382 in 2c32347

	pub fn build_logger_with_level(level: slog::Level) -> slog::Logger {
	let main_drain = if atty::is(atty::Stream::Stdout) {

std has a replacement for this: https://doc.rust-lang.org/stable/std/io/trait.IsTerminal.html