[Chapel Merge] Build bundled LLVM serially in make-install-check

Branch: refs/heads/main
Revision: 15da9ccffbcfb9534a52d3a210c80e37e6f2e89c
Author: arifthpe
Link: Build bundled LLVM serially in make-install-check by arifthpe · Pull Request #28534 · chapel-lang/chapel · GitHub
Log Message:
Build bundled LLVM serially in make-install-check (#28534)

Limit the build of the bundled LLVM in test_install.bash to a single
job to avoid OOM in nightly testing.

Since this is the limiting factor for number of jobs, increase the
number of jobs for the rest of the build to equal the number of cores.
This is as it was in Increase nightly testing parallelism by arifthpe · Pull Request #28525 · chapel-lang/chapel · GitHub,
before Add make-install-test script, reduce concurrency by arifthpe · Pull Request #28528 · chapel-lang/chapel · GitHub applied a
universal limit that still wasn't restrictive enough for LLVM.

Follow up to Add make-install-test script, reduce concurrency by arifthpe · Pull Request #28528 · chapel-lang/chapel · GitHub and
Increase nightly testing parallelism by arifthpe · Pull Request #28525 · chapel-lang/chapel · GitHub.

[trivial, not reviewed]

Compare: Comparing b10285db846fbd45d4f18daa8ec49d55197dcfca...584ad90c98e73273a0360cc835bc64d0ba95b472 · chapel-lang/chapel · GitHub

Diff:
M util/buildRelease/test_install.bash
M util/cron/test-make-install-check.bash
https://github.com/chapel-lang/chapel/pull/28534.diff