docs(ci): recommend globalTimeout instead of a CI job timeout

[Dmitry Gozman (dgozman)]

Summary

• Add a "Global timeout" section to ci.md and a note in ci-intro.md: a job-level timeout kills the run mid-flight, so the job reads as cancelled and no report is produced.
• Drop timeout-minutes from all workflow examples in ci.md, ci-intro.md and test-sharding-js.md.
• Add globalTimeout to the full config example and the options table in test-configuration-js.md.

create-playwright is updated to match in microsoft/create-playwright#181.

Fixes #42533

[Abdellah Ouadoudi (holistis)]

Just noticed this landed, along with create-playwright#181. I asked for a note in the docs and you fixed the scaffolding itself, which is the version of this that actually matters, since it means every new project gets the safe default without anyone having to read the note in the first place. Thanks for going further than the issue asked for.