Add to the triage issue to list MRs with >=15 threads via the use of GraphQL

Add to the triage issue to list MRs with >=15 threads via the use of GraphQL

FYI @alexkalderimis @kwiebers

To support any GraphQL in triage-ops we need to add GraphQL API to gitlab-triage with https://gitlab.com/gitlab-org/gitlab-triage/-/issues/195 first. Originally I brought up GraphQL as an option if the data is available that it could be able to be leveraged instead of building new APIs.