gh-95913: Edit, link and sort 3.11 WhatsNew Build section

[CAM-Gerlach]

Part of #95913

This PR copyedits, sorts and fixes/improves the syntax, cross references and links of the Build section of the What's New in Python 3.11 document. In particular, it:

• Orders the list of items more sensitively to group similar/related topics together, e.g. new build requirements, new configure flags, etc.
• Consolidates several items that contained mostly redundant/closely related information
• Adds, fixes and refines Sphinx cross references and links to external references as appropriate
• Adds appropriate Sphinx roles and other constructs
• Tweaks the text to fix grammar/wording issues
• Uses consistent, direct phrasing for easier/quicker readability

While I did read through the various Build changes in the changelog, and quite a few appeared to be of a similar magnitude to those added here, given this is not an area of my expertise and it would substantially delay the review of this PR, I elected to defer that until later.

• Issue: Edit What's New for Python 3.11 #95913

[miss-islington]

Thanks @CAM-Gerlach for the PR, and @pablogsal for merging it 🌮🎉.. I'm working now to backport this PR to: 3.11.
🐍🍒⛏🤖

[bedevere-bot]

GH-98596 is a backport of this pull request to the 3.11 branch.

[encukou]

• NaNs are part of IEEE 754, and the math functions are part of C11, so mentioning the earlier changes are redundant now.
• This is specific to CPython.

Suggested change

	* Building Python now requires:
	* A `C11 <https://en.cppreference.com/w/c/11>`_ compiler.
	`Optional C11 features
	<https://en.wikipedia.org/wiki/C11_(C_standard_revision)#Optional_features>`_
	are not required.
	(Contributed by Victor Stinner in :issue:`46656`.)
	* Support for `IEEE 754 <https://en.wikipedia.org/wiki/IEEE_754>`_
	floating point numbers.
	(Contributed by Victor Stinner in :issue:`46917`.)
	* Support for `floating point Not-a-Number (NaN)
	<https://en.wikipedia.org/wiki/NaN#Floating_point>`_,
	as the :c:macro:`!Py_NO_NAN` macro has been removed.
	(Contributed by Victor Stinner in :issue:`46656`.)
	* A `C99 <https://en.cppreference.com/w/c/99>`_
	``<math.h>`` header file providing the
	:c:func:`!copysign`, :c:func:`!hypot`, :c:func:`!isfinite`,
	:c:func:`!isinf`, :c:func:`!isnan`, and :c:func:`!round` functions
	(contributed by Victor Stinner in :issue:`45440`);
	and a :c:data:`!NAN` constant or the :c:func:`!__builtin_nan` function
	(Contributed by Victor Stinner in :issue:`46640`).
	* Building CPython now requires:
	* A `C11 <https://en.cppreference.com/w/c/11>`_ compiler and standard library.
	`Optional C11 features
	<https://en.wikipedia.org/wiki/C11_(C_standard_revision)#Optional_features>`_
	are not required.
	(Contributed by Victor Stinner in :issue:`46656`,
	:issue:`45440`, :issue:`46640`.)
	* Support for `IEEE 754 <https://en.wikipedia.org/wiki/IEEE_754>`_
	floating point numbers.
	(Contributed by Victor Stinner in :issue:`46917`.)
	* The :c:macro:`!Py_NO_NAN` macro has been removed.
	Since CPython now requires IEEE 754 floats, NaN values are always available.
	(Contributed by Victor Stinner in :issue:`46656`.)

[encukou]

Ah, too late. No big deal.

[CAM-Gerlach]

Sorry about that. I was wondering about it, but I wanted to be conservative with my initial changes since I wasn't 100% sure. I can submit a PR for you (with you co-authored on the commit) to apply it going forward, or you can if you prefer.

[encukou]

Go ahead. I might get to it later, as my task list shrinks.

[CAM-Gerlach]

Wait, your task list actually shrinks? It seems as if by invisible dark energy that my task list is perpetually expanding...

In any case, I went ahead and opened this as PR #98781, thanks.