Add pytest version to test matrix

.github/workflows/python-package.yml

@@ -17,6 +17,10 @@ jobs:
       fail-fast: false
       matrix:
         python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
+        pytest-version: ["6.*.*", "7.*.*", "8.*.*"]
+        exclude:
+          - python-version: "3.7"
+            pytest-version: "8.*.*"
 
     steps:
     - uses: actions/checkout@v3
@@ -27,7 +31,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install pytest==7.0.0
+        python -m pip install pytest==${{ matrix.pytest-version}}
         python -m pip install .
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
     - name: Test with pytest