Update peaceiris/actions-gh-pages action to v4

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
peaceiris/actions-gh-pages	action	major	v3.9.3 -> v4.0.0

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Release Notes

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

### [`v4.0.0`](https://togithub.com/peaceiris/actions-gh-pages/releases/tag/v4.0.0): actions-github-pages v4.0.0 [Compare Source](https://togithub.com/peaceiris/actions-gh-pages/compare/v3.9.3...v4.0.0) See [CHANGELOG.md](https://togithub.com/peaceiris/actions-gh-pages/blob/v4.0.0/CHANGELOG.md) for more details.

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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 becomes conflicted, or you tick the rebase/retry checkbox.

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

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

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