Accessing job's runs-on value

Is it possible to access the job’s runs-on value in an action? I imagine something like:

github_actions.context.job.runs_on

But there is no documentation as to the content of different contexts. Or is there some other way to access that variable?

The closest I’m aware of is runner.os, but that gives you only the operating system, not the specific version. Though if you know the OS you might be able to use OS-specific means to find the version.

For documentation on the available contexts, see: Context and expression syntax for GitHub Actions - GitHub Docs