[RFC]: add support for computing the derivative of cardinal sine (cosc)

## Checklist

> Please ensure the following tasks are completed before submitting a feature request.

- [x] Read and understood the [Code of Conduct][code-of-conduct].
- [x] Searched for existing issues and pull requests.
- [x] The issue name begins with `RFC:`.

## Description

> Description of the feature request.

This RFC proposes adding support for computing the derivative of [cardinal sine](https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/math/base/special/sinc). Apart from special cases, the implementation is straightforward:

```javascript
return (cospi( x ) - (sinpi( x )/(PI*x)) / x;
```

Package: `@stdlib/math/base/special/cosc`
Alias: `base.cosc`

## Related Issues

> Does this feature request have any related issues?

No.

## Questions

> Any questions for reviewers?

No.

## Other

> Any other information relevant to this feature request? This may include screenshots, references, sample output, and/or implementation notes.

Reference implementations:

- [Julia](https://github.com/JuliaLang/julia/blob/dee7d77c199c4776cf4e06afb7ce920f09ad3c8c/base/special/trig.jl#L952)

[code-of-conduct]: https://github.com/stdlib-js/stdlib/blob/develop/CODE_OF_CONDUCT.md

Start with the existing cardinal sine implementation under lib/node_modules/@stdlib/math/base/special/sinc and compare its conventions with the Julia reference implementation linked in the RFC. Add the @stdlib/math/base/special/cosc package and ensure it computes the derivative of cardinal sine, including the special cases mentioned by the issue.

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