fix: run tests for pip based workflows

Author: armandsauzay

test/action.yaml

@@ -61,7 +61,8 @@ runs:
         elif [[ -f setup.py ]]; then
           python setup.py test -- ${{ inputs.test-flags }}
         else
-          echo "No tests found"
+            pip install pytest
+            pytest ${{ inputs.test-flags }}
         fi
     # If we do have a poetry.lock, we use a poetry based workflow
     - name: install poetry