src: fewer uses of NODE_USE_V8_PLATFORM

PR-URL: https://github.com/nodejs/node/pull/30029


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Minwoo Jung <nodecorelab@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>