build: update token used for pull requests

Refs: https://github.com/nodejs/node/pull/39874#issuecomment-905538468

PR-URL: https://github.com/nodejs/node/pull/39907


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>