[Chapel Merge] Use 2 threads for make in test-docker

Branch: refs/heads/main
Revision: 5639f2780357f5b3acbdd6dd22c33795be18f455
Author: arifthpe
Link: Use 2 threads for make in test-docker by arifthpe · Pull Request #28635 · chapel-lang/chapel · GitHub
Log Message:
Use 2 threads for make in test-docker (#28635)

Bump number of threads to make -j argument in
util/cron/test-docker.bash from 1 to 2.

I think we can get away with this level of parallelism. If it works and
doesn't cause system stability issues, pushing further to 3 or even 4
could be worth trying.

[trivial, not reviewed]

Compare: Comparing 873a6c1a2a02a652623365a8f13cc3585bed77e8...5f5b5f5651c2e3ada6dc68ff491da56b7872a5a0 · chapel-lang/chapel · GitHub

Diff:
M util/cron/test-docker.bash
https://github.com/chapel-lang/chapel/pull/28635.diff