Bump vue-loader from 15.9.6 to 15.9.7

Bumps [vue-loader](https://github.com/vuejs/vue-loader) from 15.9.6 to 15.9.7.
- [Release notes](https://github.com/vuejs/vue-loader/releases)
- [Changelog](https://github.com/vuejs/vue-loader/blob/master/CHANGELOG.md)
- [Commits](vuejs/vue-loader@v15.9.6...v15.9.7)

---
updated-dependencies:
- dependency-name: vue-loader
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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