⬆️ deps: Upgrade actions/checkout action to v4.2.1.

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	patch	v4.2.0 -> v4.2.1

---

Release Notes

actions/checkout (actions/checkout)

v4.2.1

Compare Source

• Check out other refs/* by commit if provided, fall back to ref by @​orhantoy in https://github.com/actions/checkout/pull/1924

---

Configuration

📅 Schedule: Branch creation - "after 10pm every weekday,before 5am every weekday,every weekend" (UTC), 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.