Triage for gitlab-shell project

Summary

This issue is for requesting triage automation on a given project. Please link to the project needed and select from a list of triage automation rules to be added.

Project: https://gitlab.com/gitlab-org/gitlab-shell

• Automation that does not require an assignee.
  • Rescheduling of milestones (milestone refinement)
  • Labelling missed-deliverable and missed:x.y based on the scheduled milestone.
  • Labelling ~"bug" on regression and on regression:x.y.
  • Labelling ~"Accepting merge requests" for unassigned issues with a milestone.
  • Labelling priority1 and severity1 on master:broken.
  • Labelling ~"missed-SLO" on issues with ~"bug" past SLO priority target.
  • Discovery of potential and popular proposals.
  • Remind people to add labels if an issue has no labels.
• Triage reports
  • Unlabelled issue triage reports, please list assignee: @nick.thomas
  • Untriaged issue triage reports, please list assignee: @nick.thomas
  • Community Merge Requests, please list coaches: @nick.thomas
  • Group triage reports
• WIP: Infer stage and group labels from subject labels

This project is owned by groupsource code and, like the gitlab and gitaly projects, it would be useful for us to receive regular triage reports. Not every issue will be groupsource code, but a significant proportion of them will be.

In general, it's quite low-traffic, but it would still be better to have the reports than not, I think.

cc @sean_carroll

cc @patrickbajao @ashmckenzie @igor.drozdov (shell maintainers)

Originally I suggested workhorse as well, but that one's being merged into the gitlab project so we'll start getting triage reports for free.