add failing test

packages/svelte/tests/runtime-runes/samples/hmr-removal/Child.svelte

@@ -0,0 +1 @@
+<p>hello</p>

packages/svelte/tests/runtime-runes/samples/hmr-removal/_config.js

@@ -0,0 +1,21 @@
+import { flushSync } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	compileOptions: {
+		dev: true,
+		hmr: true
+	},
+
+	html: `<button>toggle</button>`,
+
+	test({ assert, target }) {
+		const button = target.querySelector('button');
+
+		flushSync(() => button.click());
+		assert.htmlEqual(target.innerHTML, `<button>toggle</button><p>hello</p>`);
+
+		flushSync(() => button.click());
+		assert.htmlEqual(target.innerHTML, `<button>toggle</button>`);
+	}
+});

packages/svelte/tests/runtime-runes/samples/hmr-removal/main.svelte

@@ -0,0 +1,11 @@
+<script>
+	import Child from './Child.svelte';
+
+	let open = $state(false);
+</script>
+
+<button onclick={() => (open = !open)}>toggle</button>
+
+{#if open}
+	<Child />
+{/if}