Draft: One-off policy to rename Ecosystem to Manage

What does this MR do and why?

Replace and remove ~"devops::ecosystem" with devopsmanage.

The Ecosystem stage was removed, and the groups moved under the Manage stage. Announcement September, 29 (Slack).

Related to #1138 (closed).

Expected impact & dry-runs

• GitLab.org https://gitlab.com/gitlab-org/quality/triage-ops/-/jobs/3339226002

  • ✅ 103 epics, aligned with expectations. Epics list
  • ✅ 6234 issues, aligned with expectations. Issues list
  • ✅ 5760 merge requests, aligned with expectations. Merge requests list

• I've tried to run this on GitLab.com, but it fails https://gitlab.com/gitlab-org/quality/triage-ops/-/jobs/3339538696

  • ❌ 0 epics, aligned with expectations. Epics list
  • ❌ 105 issues, aligned with expectations. Issues list
  • ❌ 100 merge requests, aligned with expectations. Merge requests list

Reference:

• https://gitlab.com/gitlab-org/quality/triage-ops/-/tree/master/doc/scheduled#one-off-policies
• https://gitlab.com/gitlab-org/quality/triage-ops/-/tree/master/doc/scheduled#testing-with-a-dry-run

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