Bump @wordpress/scripts from 30.20.0 to 30.21.0 (#495)

Bumps [@wordpress/scripts](https://github.com/WordPress/gutenberg/tree/HEAD/packages/scripts) from 30.20.0 to 30.21.0.
- [Release notes](https://github.com/WordPress/gutenberg/releases)
- [Changelog](https://github.com/WordPress/gutenberg/blob/trunk/packages/scripts/CHANGELOG.md)
- [Commits](https://github.com/WordPress/gutenberg/commits/@wordpress/scripts@30.21.0/packages/scripts)

---
updated-dependencies:
- dependency-name: "@wordpress/scripts"
  dependency-version: 30.21.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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