Ping inactive authors after 14 days of inactivity

What does this MR do and why?

This MR addresses two related issues, with two separate commits:

• Ping inactive authors after 14 days of inactivity on Community contribution + workflowin dev MRs
• Remove automation:author-reminded when MR is ready for review

Closes #1069 (closed), #1068 (closed).

Expected impact & dry-runs

Inactive authors should get a ping after 10 days of inactivity in their workflowin dev MR. They shouldn't receive any more pings as we set the automation:author-reminded label.

Dry-run: https://gitlab.com/gitlab-org/quality/triage-ops/-/jobs/2770590780. This would ping 218 unresponsive community contributors.

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