chore(deps): update actions/setup-node action to v6 (#2296)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/setup-node](https://redirect.github.com/actions/setup-node) |
action | major | `v4` -> `v6` |

---

### Release Notes

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

###
[`v6`](https://redirect.github.com/actions/setup-node/compare/v5...v6)

[Compare
Source](https://redirect.github.com/actions/setup-node/compare/v5...v6)

###
[`v5`](https://redirect.github.com/actions/setup-node/compare/v4...v5)

[Compare
Source](https://redirect.github.com/actions/setup-node/compare/v4...v5)

</details>

---

### Configuration

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

---

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

---

This PR was generated by [Mend Renovate](https://mend.io/renovate/).
View the [repository job
log](https://developer.mend.io/github/JoshuaKGoldberg/create-typescript-app).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0Mi4xOS45IiwidXBkYXRlZEluVmVyIjoiNDIuMTkuOSIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOlsiZGVwZW5kZW5jaWVzIl19-->

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/actions/prepare/action.yml

@@ -5,7 +5,7 @@ name: Prepare
 runs:
   steps:
     - uses: pnpm/action-setup@41ff72655975bd51cab0327fa583b6e92b6d3061 # v4
-    - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+    - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
       with:
         cache: pnpm
         node-version: 24.11.1