CI/CD leaves no run "Waiting" on GitHub after its check ended

A check restarted midway, or one whose tests were split into a different number of parts, could leave old runtime / … runs queued or in progress on the commit for good, though the check itself had passed, failed or been cancelled. Within a few minutes of a check's end, every run of it GitHub still shows open is now ended: a job's run with its job's result, an extra runtime run with the check's own, and a run of a job the check no longer has as Cancelled, "Not run: its check ended before this run of the job began." Another check of the same commit keeps its runs as they are.