feat: add `math/base/special/atandf`

[gunjjoshi]

Description

What is the purpose of this pull request?

This pull request:

• adds math/base/special/atandf, which would be the single-precision equivalent for math/base/special/atand.

float stdlib_base_atandf( const float x );

Related Issues

Does this pull request have any related issues?

This pull request:

• resolves a part of #649.

Questions

Any questions for reviewers of this pull request?

No.

Other

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

No.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• [x] Read, understood, and followed the contributing guidelines.

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@stdlib-js/reviewers