Test

`parallelize` sets numba cores to 1 #1594

Job	Run time
test (3.12, ubuntu-latest)	11m 42s
test (3.11, ubuntu-latest)	10m 24s
test (3.10, ubuntu-latest)	10m 19s
test (3.12, macos-latest, --pre, Python 3.12 (pre-release))	16m 55s
	49m 20s

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