Renaming a presubmit job triggered builds on draft pull requests

[ivanvc]

Background Slack threads: #sig-testing, #prow.

As part of etcd's migration to the prow infrastructure, I recently renamed an etcd presubmit job (pull-etcd-unit-test to pull-etcd-unit-test-amd64) in kubernetes/test-infra#32708. After merging this pull request, it triggered jobs in many pull requests.

However, it seems like the status reconciler may have a bug, as it also ran on draft pull requests. An example is etcd-io/etcd#14094: prow job

Here's the list of the jobs it ran; the ones before Jun 05 17:20:00 were automatically triggered after the renaming:
https://prow.k8s.io/job-history/gs/kubernetes-jenkins/pr-logs/directory/pull-etcd-unit-test-amd64?buildId=1798872340767969280