src: update NODE_MODULE_VERSION to 66

Major V8 updates are usually API/ABI incompatible with previous
versions. This commit adapts NODE_MODULE_VERSION for V8 6.9.

Refs: https://github.com/nodejs/CTC/blob/master/meetings/2016-09-28.md

PR-URL: https://github.com/nodejs/node/pull/21983


Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>