Description

Simplify the CI pipeline for a cleaner workflow; and avoid the parallelism limit when we add more flags to the CLI.

Most of the time, the new workflow's total duration would be shorter or similar to the previous one (longer job execution time but less queueing time¹), but sometimes, Windows Cypress tests took too long when cache misses.

TODOs:

• separatetypescript-* projects from others because type-checking takes much more time
• add node 18/20 jobs
• add tests for Nightwatch I didn't manage to get Nightwatch tests working on GitHub Actions. It was never tested before anyway, so let's skip that for this PR.
• Add more snapshots for ESLint / Prettier, now that they won't trigger more jobs in the CI matrix.
  I'd like to move that into a separate PR because it requires changing the snapshot script, so not a mere CI change.
• fix--with-tests. That should also be a separate PR.

TO DECIDE:

• Shall we scope down the Node.js 18/20 tests to only make sure that the project can be successfully created and dependencies can be installed withengine-strict flag on? Because most of the actual compatibility work is on the shoulder of the upstream projects, not us.