[CHORE] Rewrite Docker test scripts to optimize for speed and reliability

[1Copenut]

After discussing with the team, we opted to remove test-docker.js and test-a11y-docker.js from our repo in PR #7379. This was decided based on some long-tail performance issues testing Docker images on MacOS under Rosetta. This ticket is a chore reminder to rewrite those scripts in a way that more accurately tests our Docker container for the following commands:

• [ ] yarn test-ci // Runs lint, unit tests, component tests
• [ ] yarn test-cypress-a11y // Runs accessibility component tests
• [ ] yarn build // Builds our artifacts

[JasonStoltz]

We marked this as a Medium priority -- it would be highly convenient to have this working but it's not necessarily blocking us at the moment.

[github-actions[bot]]

👋 Hi there - this issue hasn't had any activity in 6 months. If the EUI team has not explicitly expressed that this is something on our roadmap, it's unlikely that we'll pick this issue up. We would sincerely appreciate a PR/community contribution if this is something that matters to you! If not, and there is no further activity on this issue for another 6 months (i.e. it's stale for over a year), the issue will be auto-closed.