Bump @babel/core from 7.20.2 to 7.21.0 in /doorbell (#285)

Bumps [@babel/core](https://github.com/babel/babel/tree/HEAD/packages/babel-core) from 7.20.2 to 7.21.0.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/main/CHANGELOG.md)
- [Commits](https://github.com/babel/babel/commits/v7.21.0/packages/babel-core)

---
updated-dependencies:
- dependency-name: "@babel/core"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]