Apply several review suggestions in `test_enums.py`
Apply several review suggestions in `test_enums.py`

Co-authored-by: Graham Markall <86e2b45e0e0bdcc23eddfa66ab0162cb095b788e@users.noreply.github.com>
IntelLabs/numba,numba/numba,IntelLabs/numba,cpcloud/numba,cpcloud/numba,IntelLabs/numba,numba/numba,cpcloud/numba,IntelLabs/numba,IntelLabs/numba,numba/numba,numba/numba,numba/numba,cpcloud/numba,cpcloud/numba