chore(deps): update node.js to v21

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [node](https://github.com/nodejs/node) | docker | minor | `20.8.0-slim` -> `20.9.0-slim` |
| [node](https://github.com/nodejs/node) | final | minor | `20.8.0-slim` -> `20.9.0-slim` |
| [node](https://nodejs.org) ([source](https://github.com/nodejs/node)) |  | minor | `20.6.0` -> `20.9.0` |

---

This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
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Reviewed-on: #10
Co-authored-by: renovate-bot <renovate-bot@dubas.dev>
Co-committed-by: renovate-bot <renovate-bot@dubas.dev>

.tool-versions

@@ -1,2 +1,2 @@
-nodejs 20.6.0
+nodejs 20.9.0
 yarn 1.22.19