release: cut v6 release

[darcyclarke]

Summary

• modify npm login prompt for OTP to align w/ v8
• update production dependencies where possible to mitigate any audit warnings

[ruyadorno]

• Release: https://github.com/npm/cli/releases/tag/v6.14.16
• node12 PR: [v12.x] deps: upgrade npm to 6.14.16 nodejs/node#41601
• node14 PR: [v14.x] deps: upgrade npm to 6.14.16 nodejs/node#41603