[3.10] gh-129641: Docs GHA build: use upload-artifact@v4 & Python 3.12 (#129642)

* [3.10] gh-129641: Switch Docs GHA build to actions/upload-artifact@v4

Add options for backwards compatibility, from the docs at:
https://github.com/actions/upload-artifact?tab=readme-ov-file#breaking-changes

* Python Tutorial typo fix (#128077)

Backported form commit: 5a584c8

This is a trivial change meant to trigger a Docs build.

* Use Python 3.12 for the 3.10 docs build

The pinned version of Sphinx requires `imghdr`, removed in Python 3.13.

---------

Co-authored-by: shallow-beach <96891913+shallow-beach@users.noreply.github.com>

Author: encukou

.github/workflows/doc.yml

@@ -38,18 +38,20 @@ jobs:
     - name: 'Set up Python'
       uses: actions/setup-python@v4
       with:
-        python-version: '3'
+        python-version: '3.12'
         cache: 'pip'
         cache-dependency-path: 'Doc/requirements.txt'
     - name: 'Install build dependencies'
       run: make -C Doc/ venv
     - name: 'Build HTML documentation'
       run: make -C Doc/ SPHINXOPTS="-q" SPHINXERRORHANDLING="-W --keep-going" html
     - name: 'Upload'
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: doc-html
         path: Doc/build/html
+        include-hidden-files: true
+        overwrite: true
 
   # Run "doctest" on HEAD as new syntax doesn't exist in the latest stable release
   doctest:

Doc/tutorial/classes.rst

@@ -325,7 +325,7 @@ Now what can we do with instance objects?  The only operations understood by
 instance objects are attribute references.  There are two kinds of valid
 attribute names: data attributes and methods.
 
-*data attributes* correspond to "instance variables" in Smalltalk, and to "data
+*Data attributes* correspond to "instance variables" in Smalltalk, and to "data
 members" in C++.  Data attributes need not be declared; like local variables,
 they spring into existence when they are first assigned to.  For example, if
 ``x`` is the instance of :class:`MyClass` created above, the following piece of