test: move test-worker-arraybuffer-zerofill to parallel

Move `test/sequential/test-worker-arraybuffer-zerofill.js` back to
`test/parallel/test-worker-arraybuffer-zerofill.js` and remove the
flaky designation.

The original issue is likely the same as other tests that time out.

Refs: #54918
Refs: #54839
Refs: #54802
PR-URL: #56053
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: LiviaMedeiros <livia@cirno.name>
Reviewed-By: Jake Yuesong Li <jake.yuesong@gmail.com>

Author: lpinca