Remove unnecessary `:func:` parentheses

[mattwang44]

Documentation

The func role's parentheses are unnecessary as Sphinx will add them to the rendered output.

.. bad
:func:`!locale.resetlocale()`

.. good
:func:`!locale.resetlocale`

We're introducing a new rule to the sphinx-lint (issue & PR) and, since sphinx-lint utilizes CPython Docs in the CI, we'd like to also fix the issue.

TODO:

• fix on main branch
• backport to 3.12
• backport to 3.13

Linked PRs

• gh-123492: Remove unnecessary :func: parentheses #123493
• [3.12] gh-123492: Remove unnecessary :func: parentheses (gh-123493) #123512
• [3.13] gh-123492: Remove unnecessary :func: parentheses (gh-123493) #123513

[hugovk]

Thanks!