feat: add constants/float32/pi-squared

[Neerajpathak07]

Progresses #649
Resolves #6070 .

Description

What is the purpose of this pull request?

This pull request:

• adds constants/float32/pi-squared

Related Issues

Does this pull request have any related issues?

This pull request:

• progresses [RFC]: Add C implementations to base special math functions (tracking issue) #649

• resolves [RFC]: add constants/float32/pi-squared #6070

Questions

Any questions for reviewers of this pull request?

No.

Other

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No.

Checklist

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

• Read, understood, and followed the contributing guidelines

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@stdlib-js/reviewers

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
constants/float32/pi-squared	$\color{green}52/52$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}0/0$ $\color{green}+100.00\%$	$\color{green}52/52$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[kgryte]

Same comments regarding related packages in newly added packages.

[Neerajpathak07]

I have made these changes for other PR's as well!! sorry for the confusion from my side.

[kgryte]

Sanity check: there are only 6 significant decimal digits for this value in single-precision?

[kgryte]

What I would do instead is

9.869604401089358f

Meaning take the double-precision value and add an f suffix. The compiler can then take care of proper rounding in C.

[Neerajpathak07]

ahh apparently while hovering over the val VS code gave its own rounded off version for this inside 7-decimal places. But I'll make this change.