simplify

packages/svelte/src/internal/client/dom/blocks/each.js

@@ -370,14 +370,12 @@ function reconcile(each_effect, array, state, anchor, flags, get_key) {
 		for (i = 0; i < length; i += 1) {
 			value = array[i];
 			key = get_key(value, i);
-			item = onscreen.get(key);
+			item = /** @type {EachItem} */ (onscreen.get(key));
 
-			if (item !== undefined) {
 			item.a?.measure();
 			(to_animate ??= new Set()).add(item);
 		}
 	}
-	}
 
 	for (i = 0; i < length; i += 1) {
 		value = array[i];