CI: various improvements (#462)

* CI: test with Python 3.12, drop Python 3.7

* CI: upgrade `actions/checkout` to v4

* CI: upgrade `actions/setup-python` to v5

.github/workflows/ci.yml

@@ -11,14 +11,14 @@ jobs:
       matrix:
         # Only test supported Python versions:
         # https://endoflife.date/python
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "pypy3.9"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "pypy3.9"]
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
 

setup.py

@@ -42,8 +42,9 @@
     'Programming Language :: Python :: 3.9',
     'Programming Language :: Python :: 3.10',
     'Programming Language :: Python :: 3.11',
-    'Programming Language :: Python :: Implementation :: PyPy',
+    'Programming Language :: Python :: 3.12',
     'Programming Language :: Python :: Implementation :: CPython',
+    'Programming Language :: Python :: Implementation :: PyPy',
 ]
 
 setup_deps = [

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 skipdist = true
 
-envlist = py{37,38,39,310,311,py39}-test
+envlist = py{38,39,310,311,312,py39}-test
 
 [pytest]
 norecursedirs = .eggs build tmp* vips-*