Bump loader-utils and rollup-plugin-vue

Bumps [loader-utils](https://github.com/webpack/loader-utils) to 1.4.2 and updates ancestor dependency [rollup-plugin-vue](https://github.com/vuejs/rollup-plugin-vue). These dependencies need to be updated together.


Updates `loader-utils` from 1.2.3 to 1.4.2
- [Release notes](https://github.com/webpack/loader-utils/releases)
- [Changelog](https://github.com/webpack/loader-utils/blob/v1.4.2/CHANGELOG.md)
- [Commits](webpack/loader-utils@v1.2.3...v1.4.2)

Updates `rollup-plugin-vue` from 3.0.0 to 6.0.0
- [Release notes](https://github.com/vuejs/rollup-plugin-vue/releases)
- [Changelog](https://github.com/vuejs/rollup-plugin-vue/blob/next/CHANGELOG.md)
- [Commits](https://github.com/vuejs/rollup-plugin-vue/commits)

---
updated-dependencies:
- dependency-name: loader-utils
  dependency-type: indirect
- dependency-name: rollup-plugin-vue
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]