Fix clippy issue

src/dynamic_data/models/battle_side.rs

@@ -188,7 +188,7 @@ impl BattleSide {
                 Some(pokemon) => old.replace(pokemon),
                 None => old.take(),
             };
-            if let Some(old_pokemon) = old.clone() {
+            if let Some(old_pokemon) = old {
                 // We need to drop the lock before calling the hook, as it might try to access the
                 // side again.
                 drop(write_lock);