Bring groups.json up-to-date

What does this MR do and why?

This MR aims to resolve #900 (closed) by bringing spec/fixtures/groups.json up-to-date.

Action items

• (If applicable) Add documentation to the handbook pages for Triage Operations =>
• (If applicable) Identify the affected groups and how to communicate to them:
  • /cc @person_or_group =>
  • Relevant Slack channels =>
  • Engineering week-in-review

Closes #900 (closed)