build: allow test-ci to run tests in parallel
Checklist
-
tests and code linting passes -
the commit message follows commit guidelines
Affected core subsystem(s)
build
Description of change
Run tests in parallel if the environment variable JOBS (which should contain a number of parallel jobs) is set.
I'd like to expand this to the actual build steps as well (and possibly even outside of the ci
scope), but it requires careful testing since it seems to break here and there for some jobs.
/cc=@nodejs/build, @trott, @bnoordhuis.