deps: upgrade npm to 7.0.0

PR-URL: https://github.com/nodejs/node/pull/35631


Reviewed-By: Ben Coe <bencoe@gmail.com>
Reviewed-By: Ruy Adorno <ruyadorno@github.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>