[RFC]: add `airy` to compute Airy functions

### Description

Airy functions are a common special function in scientific applications, particularly wave phenomena. This RFC proposes to add a single package to compute for real-valued inputs the Airy function of the first kind, Ai(x), the second kind, Bi(x), and respective derivatives, Ai'(x) and Bi'(x).

The four outputs share a lot of computation, so for similar reasons and in the style of [@stdlib/math/base/special/ellipj](https://github.com/stdlib-js/math/blob/11642395f18340deb36d03737d63e2d3da9e02b1/base/special/ellipj/lib/index.js#L58-L62), perhaps the structure that makes sense is a single package, `airy` with exports:

```
airy(x) // [ Ai(x), Ai'(x), Bi(x), Bi'(x) ]
airy.ai( x ) // Ai(x)
airy.aip( x ) // Ai'(x)
airy.bi( x ) // Bi(x)
airy.bip( x ) // Bi'(x)
airy.assign( x, out, stride, offset )
```

Exports `ai`, `aip`, `bi`, and `bip` would be convenience functions that compute all four values and throw away three.

### Related Issues

_No response_

### Questions

No.

### Other

See also:

[scipy.special.airy](https://docs.scipy.org/doc/scipy/reference/generated/scipy.special.airy.html)
[cephes airy](https://github.com/jeremybarnes/cephes/blob/60f27df395b8322c2da22c83751a2366b82d50d1/bessel/airy.c#L838-L965)

### Checklist

- [x] I have read and understood the [Code of Conduct](https://github.com/stdlib-js/stdlib/blob/develop/CODE_OF_CONDUCT.md).
- [x] Searched for existing issues and pull requests.
- [x] The issue name begins with `RFC:`.

Start by reviewing base/special/ellipj/lib/index.js for the shared-output package structure. Compare the proposed API and real-valued behavior with scipy.special.airy and the referenced Cephes implementation. Done means a new airy package exposes airy, ai, aip, bi, bip, and assign for the four Airy values and their derivatives.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.