chore(deps): update actions/setup-node action to v4 (#315)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/setup-node](https://github.com/actions/setup-node) | action | major | `v3` -> `v4` |

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### Release Notes

<details>
<summary>actions/setup-node (actions/setup-node)</summary>

### [`v4`](https://github.com/actions/setup-node/compare/v3...v4)

[Compare Source](https://github.com/actions/setup-node/compare/v3...v4)

</details>

---

### 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.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
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Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://gitea.com/gitea/blog/pulls/315
Reviewed-by: Denys Konovalov <denyskon@noreply.gitea.com>
Reviewed-by: 6543 <6543@obermui.de>
Co-authored-by: Renovate Bot <renovate-bot@gitea.com>
Co-committed-by: Renovate Bot <renovate-bot@gitea.com>

.gitea/workflows/publish-blog.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0    # Fetch all history for .GitInfo and .Lastmod
-      - uses: actions/setup-node@v3
+      - uses: actions/setup-node@v4
         with:
           node-version: 18
       - name: Build