Bump node from 16.4.2-slim to 16.6.0-slim in /docker (from PR #2383)
Bump node from 16.4.2-slim to 16.6.0-slim in /docker (from PR #2383)

Bumps node from 16.4.2-slim to 16.6.0-slim.

mozilla-services/tecken,mozilla-services/tecken,mozilla-services/tecken,mozilla-services/tecken