nodejs: switch from 14.x to 16.x to keep up with the lts release (#142915)
* nodejs: switch from 14.x to 16.x to keep up with the lts release
See: https://nodejs.org/en/about/releases/
* nodePackages: stick to nodejs-14_x while node2nix is broken on 16.x
authored by Ivan Babrou and committed by GitHub 4c60ee3d 4ff2a239