Update Node.js to v22.21.1 (#70)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| docker.io/node | final | patch | `22.21.0-alpine3.22` -> `22.21.1-alpine3.22` |

---

### 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.

---

 - [ ] <!-- 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).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0MS4xNTUuNCIsInVwZGF0ZWRJblZlciI6IjQxLjE1NS40IiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6W119-->

Reviewed-on: #70
Co-authored-by: Renovate Bot <renovate-bot@alexlebens.net>
Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

Dockerfile

@@ -1,5 +1,5 @@
 ARG REGISTRY=docker.io
-FROM ${REGISTRY}/node:22.21.0-alpine3.22 AS base
+FROM ${REGISTRY}/node:22.21.1-alpine3.22 AS base
 
 LABEL version="0.0.2"
 LABEL description="Astro based documentation website"