gh-128349: use .. data:: instead of .. class:: for pre-defined decimal Context objects

[abkmystery]

Closes gh-128349.

Updated .. class:: BasicContext to .. data:: BasicContext to correctly represent it as a predefined context object, not a class.

This ensures accurate documentation of the decimal module.

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📚 Documentation preview 📚: https://cpython-previews--128379.org.readthedocs.build/

[ghost]

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[picnixz]

Before we merge it, can you check that we never refer to those objects using the :class: role across the docs? thanks in advance.

Changes were made.

[skirpichev]

Before we merge it, can you check that we never refer to those objects using the :class: role across the docs?

$ git grep -E '(BasicContext|ExtendedContext|DefaultContext)`' Doc/
Doc/library/decimal.rst:use standard contexts, :const:`BasicContext` and :const:`ExtendedContext`. The
Doc/library/decimal.rst:   default values are copied from the :const:`DefaultContext`.  If the *flags*
Doc/whatsnew/3.3.rst:* In the context templates (:class:`~decimal.DefaultContext`,
Doc/whatsnew/3.3.rst:  :class:`~decimal.BasicContext` and :class:`~decimal.ExtendedContext`)

[picnixz]

Doc/whatsnew/3.3.rst:* In the context templates (:class:~decimal.DefaultContext,
Doc/whatsnew/3.3.rst: :class:~decimal.BasicContext and :class:~decimal.ExtendedContext)

Those two need to be changed then.

Some :class: occurrences remain.

[abkmystery]

@picnixz @skirpichev Can you please review the changes now? I had checked within the doc library folder but now checked across complete doc folder. Let me know if any further changes/corrections are needed.

[skirpichev]

@abkmystery, please avoid "update branch" button, unless you want to fix a merge conflict or to trigger CI run if your pr is old.

[abkmystery]

@skirpichev Got it. Please review the changes now.

[abkmystery]

@skirpichev Are there any further steps pending from me or will someone with authorization go through awaiting merge tagged PR and merge this? Asking as I am new to this and don't want to miss anything. Thanks

[skirpichev]

Yes, you should wait a merge.

[miss-islington-app]

Thanks @abkmystery for the PR, and @Eclips4 for merging it 🌮🎉.. I'm working now to backport this PR to: 3.12, 3.13.
🐍🍒⛏🤖

[bedevere-app]

GH-128401 is a backport of this pull request to the 3.13 branch.

[bedevere-app]

GH-128402 is a backport of this pull request to the 3.12 branch.

[Eclips4]

Thank you @abkmystery! Congratulations on your first contribution 🎊!