www/node: Update 16.5.0 -> 16.6.0

https://nodejs.org/en/blog/release/v16.6.0/

This is a security release. See
https://nodejs.org/en/blog/vulnerability/july-2021-security-releases-2/

Security: f53dab71-1b15-11ec-9d9d-0022489ad614
MFH: 2021Q3
Sponsored by: Miles AS