gh-89554: Document socket.SocketType as a class

[gaborbernat]

socket.SocketType is a class, but the documentation marks it with the .. data:: directive, so :class: cross-references to it cannot resolve against a py:class target.

This switches the entry to .. class::. It also corrects the description: SocketType is re-exported from _socket as an alias of _socket.socket, the base class of socket.socket, so isinstance(socket(...), SocketType) is true while type(socket(...)) is socket.socket itself. The current wording, "the same as type(socket(...))", is the misleading text reported in gh-88427.

This overlaps with #93288, which corrects the same sentence but keeps .. data::. This PR combines that wording fix with the role fix.

Refs: gh-89554, gh-88427. Documentation-only change, so no Misc/NEWS entry (skip news).

This file is not covered by CODEOWNERS, so cc @vstinner, who reviews most socket changes.

[gaborbernat]

For context, I am aware of gh-88427 (the SocketType documentation being called misleading) and the open deprecation proposal in #126272. This change is limited to the directive role: it switches .. data:: to .. class:: so existing :class: cross-references resolve, and leaves the deprecation question untouched. While SocketType remains public it should carry the correct role; if it is deprecated later, this can be revisited.

[read-the-docs-community]

Documentation build overview

📚 cpython-previews | 🛠️ Build #32939334 | 📁 Comparing f1bb611 against main (2f8f569)

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4 files changed

± library/array.html
± library/socket.html
± whatsnew/3.16.html
± whatsnew/changelog.html

[gaborbernat]

Amended: this now also corrects the misleading description (SocketType is the base class of socket.socket, not type(socket(...))), addressing gh-88427. That overlaps with #93288, which fixes the wording alone; this combines it with the role change.

[gaborbernat]

Backward-compatibility check. No independent :data: references were found, and SocketType is already proposed for deprecation (gh-88427). Minimal breakage.

[vstinner]

You should move the declaration at https://docs.python.org/dev/library/socket.html#socket-objects and convert methods documentation to .. method: format.

[vstinner]

For the methods below, you should add an indentation of 3 spaces, and replace .. method:: socket.xxx(...) with .. method:: xxx(...) (remove socket. prefix).