700+ CI pipelines and 30,000+ jobs for EE fork on Shared Runners

Ok, this may not be the right place for this issue ... feel free to redirect

Summary - Urgent

There are currently 700+ CI pipelines queued for shared runners project techguru/gitlab-ee -- this is not the expected result. The urgency is the resource drain w/r/t to other clients of the shared runners.

requested immediate action

If there is a convenient way to bulk-remove pending pipeline entries, that would be great.

See: https://gitlab.com/techguru/gitlab-ee/pipelines

long term action

Triage root cause and fix CI triggers

procedure to reproduce

As near as I recall, the steps I went through that caused this were:

1. fork EE
2. set project setting to enable mirror repository from gitlab-org/gitlab-ee
3. fetch project from upstream using sourcetree GUI app
4. create new branch from tip of master branch
5. pull changes from gitlab-ce branch to be integrated
6. push the new branch

What I see now is 700+ pipelines, which appear to be one for each tag in the gitlab-ee repo ... not sure what triggered that. The project settings for mirror repository DO NOT HAVE Trigger pipelines for mirror updates enabled.

For the moment, I have disabled shared runners on the fork to prevent any further unnecessary CI pipelines from running.

/cc @stanhu @pcarranza @ernstvn