Update peaceiris/actions-gh-pages action to v4

[xdev-renovate]

This PR contains the following updates:

Package	Type	Update	Change
peaceiris/actions-gh-pages	action	major	v3 -> v4

---

Release Notes

peaceiris/actions-gh-pages (peaceiris/actions-gh-pages)

### [`v4`](https://togithub.com/peaceiris/actions-gh-pages/compare/v3...v4) [Compare Source](https://togithub.com/peaceiris/actions-gh-pages/compare/v3...v4)

---

Configuration

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

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ 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 has been generated by Renovate Bot.