The poller job set GITHUB_RUN_ID in env: to point at the CI run.
The Actions runner sets the GITHUB_* defaults itself and ignores
the override. Thus the poller read its own run id and watched
itself. Its own run stays in_progress while the poller runs, so
runs_all_completed() was never true. The comment froze at
'waiting for jobs to start' and the job burned its full 3000s
timeout on every PR.
Rename the variable to CI_RUN_ID. Also drop the GITHUB_REPOSITORY
override — it was a no-op for the same reason, and the runner
default already holds the correct value.
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