ci: upgrade actions and add Python 3.12

.github/workflows/ci.yml

@@ -17,15 +17,15 @@ jobs:
     strategy:
       matrix:
         runner: ['ubuntu-latest']
-        python-version: [ '3.7', '3.8', '3.9', '3.10', '3.11' ]
+        python-version: [ '3.7', '3.8', '3.9', '3.10', '3.11', '3.12' ]
         include:
           - runner: 'ubuntu-20.04'
             python-version: '3.6'
 
     steps:
-    - 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 }}
     - name: Install pip dependencies
@@ -61,9 +61,9 @@ jobs:
     permissions:
       id-token: write  # IMPORTANT: this permission is mandatory for trusted publishing
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Python 3.9
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: '3.9'
     - name: Build PyPI package