Queue-flake anchor: scripts/root-index.test.ts #23797

scripts/root-index.test.ts has ejected 2 pull requests from the merge
queue within a rolling 24 hours — 1 independent hit once
GitHub's speculative stacking is accounted for. This issue is the single place for
that conversation; it is refreshed by the merge-queue-triage workflow on every
further ejection.

⚠️ Queue depth is not evidence. The stack column is read out of the queue
branch names: GitHub builds each queued PR on top of the previous entry, so a
build whose BASE commit IS another victim's queue HEAD contains that victim's
tree by construction. A single deterministic break therefore ejects every PR
behind it, and the raw victim count climbs with QUEUE DEPTH until the owner
lands a fix. Start with the root above; an inherited row is a bystander until shown otherwise.

This issue is a NAME, not a diagnosis. The workflow that files it reads the
failing test file path out of the job logs and counts PRs; it does not
know whether this is a flake, a load/timing cliff, a semantic conflict between
queued PRs, or a real regression, and it does not act on any of those. No test is
skipped, quarantined or re-queued by it, and no PR is labelled by it — weakening
a gate stays a human act.

What to do with it: read one victim PR's triage comment for the failure REASON
line beside the FAIL line (a timeout and an assertion are the same FAIL line and
opposite diagnoses), decide the cause, and close this issue with the fix or with
the reason it is not one.

Last refreshed by queue build 38841078457 (PR #23783).

Filed by the merge-queue-triage workflow (#4859, aggregation #10128).