Bump @vue/test-utils from 2.0.0-rc.18 to 2.4.3

Bumps [@vue/test-utils](https://github.com/vuejs/test-utils) from 2.0.0-rc.18 to 2.4.3.
- [Release notes](https://github.com/vuejs/test-utils/releases)
- [Commits](vuejs/test-utils@v2.0.0-rc.18...v2.4.3)

---
updated-dependencies:
- dependency-name: "@vue/test-utils"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>