chore: add changeset and comment (#14040)

for #14026

.changeset/small-bobcats-add.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: don't access `requestAnimationFrame` until needed to reduce need for mocks during testing

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

@@ -7,6 +7,9 @@ const now = BROWSER ? () => performance.now() : () => Date.now();
 
 /** @type {Raf} */
 export const raf = {
+	// don't access requestAnimationFrame eagerly outside method
+	// this allows basic testing of user code without JSDOM
+	// bunder will eval and remove ternary when the user's app is built
 	tick: /** @param {any} _ */ (_) => (BROWSER ? requestAnimationFrame : noop)(_),
 	now: () => now(),
 	tasks: new Set()