Test

`parallelize` sets numba cores to 1 #1597

Job	Run time
test (3.10, ubuntu-latest)	6m 16s
test (3.11, ubuntu-latest)	7m 25s
test (3.12, macos-latest, --pre, Python 3.12 (pre-release))	9m 46s
test (3.12, ubuntu-latest)	8m 13s
	31m 40s

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