Update regenerate-library.yml

switch to using pipenv

.github/workflows/regenerate-library.yml

@@ -18,7 +18,8 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install -r requirements.txt
+          pip install pipenv
+          pipenv install
       - name: Delete folder
         run: |
           rm -rf meraki