Update dependency firebase-functions to v5.1.1

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
firebase-functions	5.1.0 -> 5.1.1

---

Release Notes

firebase/firebase-functions (firebase-functions)

### [`v5.1.1`](https://togithub.com/firebase/firebase-functions/releases/tag/v5.1.1) [Compare Source](https://togithub.com/firebase/firebase-functions/compare/v5.1.0...v5.1.1) - Fix retry in event triggered functions. ([#​1463](https://togithub.com/firebase/firebase-functions/issues/1463)) - Expose retry configuration in v2 RTDB trigger ([#​1588](https://togithub.com/firebase/firebase-functions/issues/1588)) - Fix CORS options for v2 callable functions ([#​1564](https://togithub.com/firebase/firebase-functions/issues/1564)) - Remove invalid `enforceAppCheck` option for v2 onRequest trigger ([#​1477](https://togithub.com/firebase/firebase-functions/issues/1477))

---

Configuration

📅 Schedule: Branch creation - "after 3am and before 7am" in timezone America/Denver, Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.