test: mark cpu-prof-dir-worker flaky on all

Refs: https://github.com/nodejs/node/issues/27611#issuecomment-613100468

PR-URL: https://github.com/nodejs/node/pull/32828


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>