allow len without is_empty

src/catch/mod.rs

@@ -132,6 +132,7 @@ pub struct CatchStrains {
 impl CatchStrains {
     /// Returns the number of strain peaks per skill.
     #[inline]
+    #[allow(clippy::len_without_is_empty)]
     pub fn len(&self) -> usize {
         self.movement.len()
     }