chore(deps): update node.js to v21 - autoclosed

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
node	final	major	18-alpine -> 21-alpine
node	stage	major	18-alpine -> 21-alpine

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Release Notes

nodejs/node (node)

### [`v21`](https://togithub.com/nodejs/node/blob/HEAD/CHANGELOG.md#2016-01-21-Version-426-Argon-LTS--TheAlphaNerd) Moved to doc/changelogs/CHANGELOG_V4.md#4.2.6. ### [`v20`](https://togithub.com/nodejs/node/blob/HEAD/CHANGELOG.md#2016-05-06-Version-01214-Maintenance--rvagg) Moved to doc/changelogs/CHANGELOG_V012.md#0.12.14. ### [`v19`](https://togithub.com/nodejs/node/blob/HEAD/CHANGELOG.md#2015-03-19-Version-160-chrisdickinson) Moved to doc/changelogs/CHANGELOG_IOJS.md#1.6.0.

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Configuration

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