MAINT: align test_dispatcher s390x targets with _umath_tests_mtargets

[charris]

Backport of #24772.

This updates https://github.com/numpy/numpy/blob/main/numpy/core/tests/test_cpu_dispatcher.py#L12 targets matching what is set at https://github.com/numpy/numpy/blob/main/numpy/core/meson.build#L688 (i.e. adding VE and VXE).

This was discovered when testing an s390x build with optimization on.

[rgommers]

The one test failure on TravisCI looks real, as noted on the original PR at #24772 (comment)

_______________________________ test_dispatcher ________________________________
...
>       assert_equal(test["func"], "func" + highest_sfx)
E       AssertionError: 
E       Items are not equal:
E        ACTUAL: 'func'
E        DESIRED: 'func_VXE'
all_sfx    = ['func_VXE', 'func_VX']
feature    = 'SSE2'
highest_sfx = '_VXE'
targets    = ('SSE2', 'SSE41', 'AVX2', 'VSX', 'VSX2', 'VSX3', ...)
test       = {'all': ['func'], 'func': 'func', 'func_xb': 'nobase', 'var': 'var', ...}
../../builds/venv/lib/python3.9/site-packages/numpy-1.26.0-py3.9-linux-s390x.egg/numpy/core/tests/test_cpu_dispatcher.py:32: AssertionError

[seiko2plus]

The #24814 backport failed a test on the travis s390x. Might be a problem with the test

My bad, VX/VXE CPU features were not tested before and I have included the meson script without updating the distutils dispatch-able sources .

[charris]

Thanks for the update Sayed.