Feat: add pytest pip install to pipeline

.github/workflows/python-package.yml

@@ -27,6 +27,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
+        python -m pip install pytest
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
     - name: Test with pytest 
       run: |