pyinstaller should pack it to allow running the tests, but doesn't
pack the tests themselves and thus doesn't find the `import` statements
that use `numpy.core._multiarray_tests`.

This makes sure that pyinstaller will ship `numpy.core._multiarray_tests`
in any case.

NumPy switched to using pytest in 2018 and nose has been unmaintained
for many years. We have kept NumPy's nose support to avoid breaking
downstream projects who might have been using it and not yet switched to
pytest or some other testing framework. With the arrival of Python 3.12,
unpatched nose will raise an error. It it time to move on.

Decorators removed

- raises
- slow
- setastest
- skipif
- knownfailif
- deprecated
- parametrize
- _needs_refcount

These are not to be confused with pytest versions with similar names,
e.g., pytest.mark.slow, pytest.mark.skipif, pytest.mark.parametrize.

Functions removed

- Tester
- import_nose
- run_module_suite

Adding this special hook file tells PyInstaller what files a self contained
NumPy application needs to run. A test is included to verify that the hook still
finds all necessary files.

Closes #17184.