Bump cross-spawn and @yarnpkg/core (#264)

Bumps [cross-spawn](https://github.com/moxystudio/node-cross-spawn) and [@yarnpkg/core](https://github.com/yarnpkg/berry/tree/HEAD/packages/yarnpkg-core). These dependencies needed to be updated together.

Updates `cross-spawn` from 7.0.3 to 7.0.6
- [Changelog](https://github.com/moxystudio/node-cross-spawn/blob/master/CHANGELOG.md)
- [Commits](moxystudio/node-cross-spawn@v7.0.3...v7.0.6)

Updates `@yarnpkg/core` from 4.1.4 to 4.1.6
- [Release notes](https://github.com/yarnpkg/berry/releases)
- [Changelog](https://github.com/yarnpkg/berry/blob/master/CHANGELOG.md)
- [Commits](https://github.com/yarnpkg/berry/commits/@yarnpkg/core/4.1.6/packages/yarnpkg-core)

---
updated-dependencies:
- dependency-name: cross-spawn
  dependency-type: indirect
- dependency-name: "@yarnpkg/core"
  dependency-type: indirect
...

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