Fix lint warning for elided lifetimes

Author: djc

src/ansi.rs

@@ -189,7 +189,7 @@ fn find_ansi_code_exclusive(it: &mut Peekable<CharIndices>) -> Option<(usize, us
 
 /// Helper function to strip ansi codes.
 #[cfg(feature = "alloc")]
-pub fn strip_ansi_codes(s: &str) -> Cow<str> {
+pub fn strip_ansi_codes(s: &str) -> Cow<'_, str> {
     let mut char_it = s.char_indices().peekable();
     match find_ansi_code_exclusive(&mut char_it) {
         Some(_) => {