simplify test (#10538)

Co-authored-by: Rich Harris <rich.harris@vercel.com>

packages/svelte/tests/runtime-runes/samples/store-subscribe-effect-init/main.svelte

@@ -1,18 +1,14 @@
 <script>
-	import { untrack } from 'svelte';
 	import { writable } from 'svelte/store';
 	import { log } from './log';
 
-	const storeCount = writable(0)
-	let count = $state(0);
+	const count = writable(0);
+	let ran = 0;
 
 	$effect(() => {
-		$storeCount;
-		untrack(() => {
-			count++;
-			log.push(count);
-		});
+		$count;
+		log.push(++ran);
 	});
 </script>
 
-<button on:click={() => $storeCount++}>increment</button>
+<button on:click={() => $count++}>increment</button>