chore(deps): pin node.js to 21.0.0 (#244)

[![Mend
Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [node](https://togithub.com/nodejs/node) | engines | pin | [`20 \|\|
21` -> `21.0.0`](https://renovatebot.com/diffs/npm/node/v21.0.0/v21.0.0)
|

Add the preset `:preserveSemverRanges` to your config if you don't want
to pin your dependencies.

---

### 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 has been generated by [Mend
Renovate](https://www.mend.io/free-developer-tools/renovate/). View
repository job log
[here](https://developer.mend.io/github/Johannes-Andersen/Johannes).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy4xOS4yIiwidXBkYXRlZEluVmVyIjoiMzcuMTkuMiIsInRhcmdldEJyYW5jaCI6Im1haW4ifQ==-->

---------

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

Author: renovate[bot]

.nvmrc

@@ -1 +1 @@
-20.8.1
+21.0.0

package-lock.json

@@ -11,7 +11,7 @@
     "format:check": "prettier --check \"**/*.{ts,tsx,js,md}\""
   },
   "engines": {
-    "node": "20 || 21",
+    "node": "21.0.0",
     "npm": "9 || 10"
   },
   "dependencies": {