Update codecov/codecov-action action to v4

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
codecov/codecov-action	action	major	v3 -> v4

---

[!WARNING] Some dependencies could not be looked up. Check the warning logs for more information.

---

Release Notes

codecov/codecov-action (codecov/codecov-action)

### [`v4`](https://togithub.com/codecov/codecov-action/compare/v3...v4) [Compare Source](https://togithub.com/codecov/codecov-action/compare/v3...v4)

---

Configuration

📅 Schedule: Branch creation - "every weekend" (UTC), Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR becomes conflicted, 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 has been generated by Mend Renovate. View repository job log here.