fix: don't log `await_reactivity_loss` warning when signal is read in `untrack` (#16385)

* fix: don't log `await_reactivity_loss` warning when signal is read in `untrack`

* add test

* fix

.changeset/big-readers-lie.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: don't log `await_reactivity_loss` warning when signal is read in `untrack`

packages/svelte/src/internal/client/runtime.js

@@ -609,7 +609,7 @@ export function get(signal) {
 			var tracking = (current_async_effect.f & REACTION_IS_UPDATING) !== 0;
 			var was_read = current_async_effect.deps?.includes(signal);
 
-			if (!tracking && !was_read) {
+			if (!tracking && !untracking && !was_read) {
 				w.await_reactivity_loss(/** @type {string} */ (signal.label));
 
 				var trace = get_stack('TracedAt');

packages/svelte/tests/runtime-runes/samples/async-reactivity-loss/_config.js

@@ -6,11 +6,14 @@ export default test({
 		dev: true
 	},
 
-	html: `<button>a</button><button>b</button><p>pending</p>`,
+	html: `<button>a</button><button>b</button><button>c</button><p>pending</p>`,
 
 	async test({ assert, target, warnings }) {
 		await tick();
-		assert.htmlEqual(target.innerHTML, '<button>a</button><button>b</button><h1>3</h1><p>3</p>');
+		assert.htmlEqual(
+			target.innerHTML,
+			'<button>a</button><button>b</button><button>c</button><h1>6</h1><p>6</p>'
+		);
 
 		assert.equal(
 			warnings[0],

packages/svelte/tests/runtime-runes/samples/async-reactivity-loss/main.svelte

@@ -1,18 +1,21 @@
 <script>
+	import { untrack } from 'svelte';
 	let a = $state(1);
 	let b = $state(2);
+	let c = $state(3);
 
-	async function a_plus_b() {
+	async function a_plus_b_plus_c() {
-		return await a + await b;
+		return await a + await b + await untrack(() => c);
 	}
 </script>
 
 <button onclick={() => a++}>a</button>
 <button onclick={() => b++}>b</button>
+<button onclick={() => c++}>c</button>
 
 <svelte:boundary>
-	<h1>{await a_plus_b()}</h1>
+	<h1>{await a_plus_b_plus_c()}</h1>
-	<p>{await a + await b}</p>
+	<p>{await a + await b + await c}</p>
 
 	{#snippet pending()}
 		<p>pending</p>