As a part of [Vue.js 3 migration](https://about.gitlab.com/company/team/structure/working-groups/vuejs-3-migration/) we want to ensure we're capable of running our **unit test** suites using `@vue/compat` for all relevant projects: * [x] gitlab-ui * [x] gitlab * [x] customer portal * [x] design.gitlab.com This includes both introducing relevant CI/CD pipelines and making sure our tests are compatible both with Vue.js 2 & Vue.js 3