Update lint-library-generator.yml

Fix pipenv logic for matrixed tests.

.github/workflows/lint-library-generator.yml

@@ -38,7 +38,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         python -m pip install pipenv
-        pipenv install --deploy
+        pipenv install --python ${{ matrix.python-version }}
         pipenv install flake8 pytest
     - name: Lint with flake8
       run: |