Revert "Skip pthread_cond_busywait test in browser tests (#589)"

This reverts commit 1377a93.

Author: kateinoigakukun

test/scripts/browser-test/harness.mjs

@@ -19,9 +19,6 @@ import url from "node:url";
 import { chromium } from 'playwright';
 
 const SKIP_TESTS = [
-    // "poll_oneoff" can't be implemented in the browser
-    "libc-test/functional/pthread_cond",
-    "libc-test/functional/pthread_cond_busywait",
     // atomic.wait32 can't be executed on the main thread
     "libc-test/functional/pthread_mutex",
     "libc-test/functional/pthread_tsd",