[github-actions] combine simulation workflows into simulation.yml (openthread#13097)

This commit combines simulation-1.1.yml and simulation-1.4.yml into
a single simulation.yml workflow.

The combined workflow includes:
- ot-commissioner (from 1.1)
- simulation-local-host (from 1.1)
- channel-manager-csl (from 1.4)
- expects (renamed from 1.4's expects)

The expects job from 1.1 is removed as requested. The jobs now rely
on the project's default THREAD_VERSION instead of explicitly
setting it in the environment. Artifact naming is updated to ensure
unique coverage files are generated and correctly merged by the
unified upload-coverage job.

Author: jwhui