Update Github actions for testing gaarf-py

* Add Python 3.8 and 3.12 to the matrix
* Install pytest-mock

Change-Id: I6c3142ce1f0dff6fc7ff35983bc96b173eab59c0

.github/workflows/pytest.yaml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
 
     steps:
       - uses: actions/checkout@v3
@@ -20,7 +20,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install pytest
+          pip install pytest pytest-mock
           if [ -f py/requirements.txt ]; then pip install --require-hashes -r py/requirements.txt --no-deps; fi
       - name: Test with pytest
         run: |