avoid console.error, use Bun.write(Bun.stderr, ...) instead

This should fix failures of the new test in CI because of escape
sequences injected by console.error.

Once bun-debug is fixed to print debug output to stderr, this test
will need adjusting.

test/js/bun/io/timed-stderr-output.js

@@ -1,4 +1,4 @@
 for (let i = 0; i <= 20; i++) {
-  console.error(i);
+  await Bun.write(Bun.stderr, i + "\n");
   await new Promise(r => setTimeout(r, 100));
 }