BLD: Meson `__config__` generation (#22769)

Add functionality to autogenerate build information for a Meson-based build.

In order to add new information, do the following:
- Add the information as an argument in `numpy/meson.build`
- Modify `__config__.py.in` to accept the new argument

Note that SIMD information is added to config, but is WIP/empty,
because  `__cpu*` lists are not yet populated as meson does not build
SIMD features yet.

There are two display modes:

    - `stdout`: Uses `PyYaml` to display in a human friendly
       format. Uses `json` if `PyYaml` is not installed
    - `dicts`: Returns a `dict` object

Things will work fine without `pyyaml` installed, an unobtrusive
warning is displayed that the printed output will look better
with `pyyaml`.

[ci skip]

0 files changed, 0 insertions, 0 deletions