Fix: Ignore non-http/https protocols in Service Worker handleFetch (#39507)

app/javascript/mastodon/service_worker/caching.ts

@@ -18,6 +18,10 @@ export async function cacheRoot() {
 export function handleFetch(event: FetchEvent) {
   const url = new URL(event.request.url);
 
+  if (url.protocol !== 'http:' && url.protocol !== 'https:') {
+    return;
+  }
+
   if (url.pathname === '/auth/sign_out') {
     event.respondWith(handleLogout(event));
   } else if (/intl\/.*\.js$/.test(url.pathname)) {