fix: remove pip cache from json2md workflow

Author: zhaojing1987

.github/workflows/json2md.yml

@@ -20,7 +20,6 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: "3.x"
-          cache: 'pip'
 
       - name: Install unzip utility
         run: sudo apt-get install unzip