Use fetch() in a way that works for file URLs (#3071)

fetch returns a response code of 0 when it successfully loads a `file://` resource.

This means we can't just rely on `response.ok`.

Required for https://github.com/element-hq/element-call/issues/2994

src/soundUtils.ts

@@ -7,6 +7,8 @@ Please see LICENSE in the repository root for full details.
 
 import { logger } from "matrix-js-sdk/src/logger";
 
+import { isFailure } from "./utils/fetch";
+
 type SoundDefinition = { mp3?: string; ogg: string };
 
 export type PrefetchedSounds<S extends string> = Promise<
@@ -49,7 +51,7 @@ export async function prefetchSounds<S extends string>(
       const response = await fetch(
         preferredFormat === "ogg" ? ogg : (mp3 ?? ogg),
       );
-      if (!response.ok) {
+      if (isFailure(response)) {
         // If the sound doesn't load, it's not the end of the world. We won't play
         // the sound when requested, but it's better than failing the whole application.
         logger.warn(`Could not load sound ${name}, response was not okay`);