(Abuse Ruby) Add team labels based on feature labels

This requires https://gitlab.com/gitlab-org/gitlab-triage/merge_requests/75

Dry-run looks good: https://gitlab.com/gitlab-org/quality/triage-ops/-/jobs/121558306

It's blazing fast, too. It's under 2 minutes including setting up! The actual run maybe only took 30 seconds or even less.

• We don't do anything if there's already at least one team labels amongst the 6 teams here.
• If an issue has features across two teams or more, add all the team labels which applicable.
• People are free to remove team labels, and the bot won't add any labels back as long as it still has at least one team labels.
• We're making 6 pointless API calls to query non-existing labels: section#manage, section#plan, and so on, but I think that's fine.
• I added encoding to ~Create because I think that makes sense and it's useful to show in the dry-run. We can remove it if this is not desirable. Here's the dry-run: https://gitlab.com/gitlab-org/quality/triage-ops/-/jobs/121558306

Closes #74 (closed)