Add explicit support for Python 3.12 (#28)

* Add explicit support for Python 3.12

* Drop support for Python 3.8. Note NumPy versions that support Python 3.12 don't support Python 3.8.

.github/workflows/main.yml

@@ -13,16 +13,14 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.9, '3.10', '3.11']
+        python-version: [3.9, '3.10', '3.11', '3.12']
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
-    - name: Install the latest Pip and Wheel
-      run: pip install --upgrade pip wheel
     - name: Set up Poetry
       uses: abatilo/actions-poetry@v2
     - name: Check package setup

.gitignore

@@ -2,6 +2,6 @@ build
 dist
 
 # codespaces:
-pythonenv3.8
+pythonenv3.9
 
 poetry.lock

pyproject.toml

@@ -18,16 +18,16 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
     "Topic :: Scientific/Engineering",
     "Topic :: Scientific/Engineering :: Artificial Intelligence",
 ]
 
 [tool.poetry.dependencies]
-python = "^3.8"
+python = "^3.9,<3.13"  # Specify an upper limit, otherwise newer NumPy versions can't be installed.
 numpy = "^1.21"  # For NumPy Typing.
 
 [tool.poetry.group.test]