Bump @babel/plugin-transform-modules-systemjs in /tests/fable

Bumps [@babel/plugin-transform-modules-systemjs](https://github.com/babel/babel/tree/HEAD/packages/babel-plugin-transform-modules-systemjs) from 7.15.4 to 7.29.4.
- [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/v7.29.4/packages/babel-plugin-transform-modules-systemjs)

---
updated-dependencies:
- dependency-name: "@babel/plugin-transform-modules-systemjs"
  dependency-version: 7.29.4
  dependency-type: indirect
...

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