gh-37270: Allow python 3.12 and scipy 1.12
    
This is a minimal PR to allow building with python 3.12, given the
circumstances surrounding #36181.

I've tested this works with system python 3.12 by:
```
./bootstrap
./configure --disable-doc --disable-editable --enable-system-site-
packages
env 'MAKE=make -j36' make
./sage -tp 36 --all
./sage -tp 36 --all --long
```

It only gave the expected failures in
`src/sage/matroids/database_collections.py` from #37140.

Since scipy 1.12 works ok after #37123 and it's just a one-liner to
change the required version, I included it here.

No attempt is made at upgrading anything in sage-the-distro.

### 📝 Checklist

- [x] The title is concise, informative, and self-explanatory.
- [x] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.

EDIT: rebased on top of #36983 to address reviewer suggestion.
    
URL: #37270
Reported by: Gonzalo Tornaría
Reviewer(s): Aliaksei Urbanski, Gonzalo Tornaría, Tobias Diez

Author: Release Manager

build/pkgs/python3/SPKG.rst

@@ -8,7 +8,7 @@ By default, Sage will try to use system's ``python3`` to set up a virtual
 environment, a.k.a. `venv <https://docs.python.org/3.10/library/venv.html>`_
 rather than building a Python 3 installation from scratch.
 
-Sage will accept versions 3.9.x to 3.11.x.
+Sage will accept versions 3.9.x to 3.12.x.
 
 You can also use ``--with-python=/path/to/python3_binary`` to tell Sage to use
 ``/path/to/python3_binary`` to set up the venv. Note that setting up the venv requires

build/pkgs/python3/spkg-configure.m4

@@ -2,7 +2,7 @@ SAGE_SPKG_CONFIGURE([python3], [
    m4_pushdef([MIN_VERSION],               [3.9.0])
    m4_pushdef([MIN_NONDEPRECATED_VERSION], [3.9.0])
    m4_pushdef([LT_STABLE_VERSION],         [3.12.0])
-   m4_pushdef([LT_VERSION],                [3.12.0])
+   m4_pushdef([LT_VERSION],                [3.13.0])
    AC_ARG_WITH([python],
                [AS_HELP_STRING([--with-python=PYTHON3],
                                [Python 3 executable to use for the Sage venv; default: python3])])

build/pkgs/scipy/install-requires.txt

@@ -4,4 +4,4 @@
 # deprecations cannot be introduced in micro releases.
 # SciPy devs wait "at least 6 months", "in practice two (minor) releases"
 # from deprecation to removal of a feature.
-scipy >=1.5, <1.12
+scipy >=1.5

m4/pyproject_toml_metadata.m4

@@ -17,4 +17,4 @@ classifiers = [
     "Topic :: Scientific/Engineering :: Mathematics",
 ]
 urls = {Homepage = "https://www.sagemath.org"}
-requires-python = ">=3.9, <3.12"
+requires-python = ">=3.9, <3.13"

pkgs/sage-setup/pyproject.toml

@@ -22,7 +22,7 @@ classifiers = [
     "Topic :: Scientific/Engineering :: Mathematics",
 ]
 urls = {Homepage = "https://www.sagemath.org"}
-requires-python = ">=3.9, <3.12"
+requires-python = ">=3.9, <3.13"
 dependencies = []
 dynamic = ["version"]
 

src/setup.cfg.m4

@@ -9,7 +9,7 @@ license_files = LICENSE.txt
 include(`setup_cfg_metadata.m4')dnl'
 
 [options]
-python_requires = >=3.9, <3.12
+python_requires = >=3.9, <3.13
 install_requires =
     SPKG_INSTALL_REQUIRES_sage_conf
     SPKG_INSTALL_REQUIRES_six