lib: cosmetic change to builtinLibs list for maintainability

This is a largely cosmetic change suggested for easier
maintainability of the builtinLibs list. While the
QUIC PR no longer modifies this list, the original version
of the PR did and the fact that all of the entries were
bundled up into the same lines meant that adding one
forced a larger change to all. With this PR, when we
want to add a new built-in, it won't impact any of the
others.

PR-URL: https://github.com/nodejs/node/pull/33106


Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Anna Henningsen <anna@addaleax.net>