Fix Python 2.7 test workflow

https://github.com/actions/setup-python/issues/672#issuecomment-1607332070

.github/workflows/test.yaml

@@ -23,10 +23,22 @@ jobs:
         uses: actions/checkout@v3
 
       - name: Set up Python ${{ matrix.py_version }}
+        if: matrix.py_version != '2.7'
         uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.py_version }}
 
+      - name: Set up Python 2.7
+        if: matrix.py_version == '2.7'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            python2.7 python2.7-dev python2-pip-whl
+          sudo ln -sf python2.7 /usr/bin/python
+          export PYTHONPATH=`echo /usr/share/python-wheels/pip-*py2*.whl`
+          sudo --preserve-env=PYTHONPATH python -m pip install --upgrade pip setuptools wheel
+          sudo chown -R $USER /usr/local/lib/python2.7
+
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip