auto-rebase: cut a release + promote channel for the eligibility fix

[don-petry]

Part of #926. Blocked by the three preceding sub-issues (code + tests must land first).

Per docs/release/versioning.md (in petry-projects/.github-private): cut a new auto-rebase release for this change (cut-release.sh auto-rebase <version> --channel next) and promote it through the ring sequence to stable once verified, so the fix actually reaches consumer repos pinned to the moving channel tags. Coordinate with petry-projects/.github-private#1416's repo-template fix (issue #1439 there) so newly-scaffolded repos get it too.

[don-petry]

Closing manually — cutting a real production release/channel-promotion is not something dev-lead should do autonomously, and it correctly said so (see its comment above: no in-repo code change, lacks release-manager bypass, ring promotion is telemetry-gated).

Cut and pushed directly:

• auto-rebase/v2.3.0 (immutable release, commit de298aba1)
• auto-rebase/v2-ring0 → v2.3.0

v2-next already carried the fix (this repo and .github-private both dogfood on v2-next, so they've had it live since #931 merged). This promotes it one ring further (ring0) toward the rest of the fleet. Continuing the promotion to ring1 → stable should follow this org's normal telemetry-gated, multi-day cadence — not done in one sitting here.