fix: remove pip cache from docs workflow (no requirements.txt in sparse-checkout)

Author: shijiashuai

.github/workflows/pages.yml

@@ -48,7 +48,6 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.11'
-          cache: 'pip'
 
       - name: Install Python dependencies
         run: |