Update actions/checkout action to v4

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v3.6.0 -> v4.0.0

---

Release Notes

actions/checkout (actions/checkout)

### [`v4.0.0`](https://togithub.com/actions/checkout/blob/HEAD/CHANGELOG.md#v400) [Compare Source](https://togithub.com/actions/checkout/compare/v3.6.0...v4.0.0) - [Support fetching without the --progress option](https://togithub.com/actions/checkout/pull/1067) - [Update to node20](https://togithub.com/actions/checkout/pull/1436)

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), 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.

---

This PR has been generated by Mend Renovate. View repository job log here.

[cloudflare-workers-and-pages[bot]]

Deploying with    Cloudflare Pages

Latest commit:	db26fad
Status:	✅  Deploy successful!
Preview URL:	https://3b321684.mmmm-a0e.pages.dev
Branch Preview URL:	https://renovate-actions-checkout-4.mmmm-a0e.pages.dev

View logs

[github-actions[bot]]

Latest commit:	e7c94f6 ( base: d880eaf + head: db26fad )
Status:	✅  Deploy successful!
Preview URL:	https://44b36e2c.mmmm-a0e.pages.dev
PR Preview URL:	https://pull-33-merge.mmmm-a0e.pages.dev

View workflow logs View Cloudflare logs