fix warnings in fuzzers

fuzz/atom/parser/fuzz.rs

@@ -1,3 +1,4 @@
+#![deny(unused_imports)]
 #![allow(clippy::missing_safety_doc)]
 
 use core::slice;

fuzz/atom/vercmp/fuzz.rs

@@ -1,9 +1,8 @@
+#![deny(unused_imports)]
+
 use core::slice;
-use gentoo_utils::{
-    Parseable,
-    atom::{Atom, Version},
-};
-use mon::{Parser, ParserFinishedError, input::InputIter};
+use gentoo_utils::{Parseable, atom::Version};
+use mon::{Parser, input::InputIter};
 use std::{
     cmp::Ordering,
     io::{BufRead, BufReader, Write},