chore: clippy fixes - allow should_implement_trait and collapse nested if

crates/xy-supervisor/src/backoff.rs

@@ -16,6 +16,7 @@ impl Backoff {
         }
     }
 
+    #[allow(clippy::should_implement_trait)]
     pub fn next(&mut self) -> Duration {
         let next = match self.current {
             None => self.initial,