chore(docs): update docs ci

Author: loonghao

.github/workflows/publish_docs.yml

@@ -12,7 +12,10 @@ jobs:
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0
-      - uses: actions/setup-python@v3
+      - name: Set up Python
+        uses: actions/setup-python@v3
+        with:
+          python-version: '3.9'
       - run: pip install --upgrade pip && python -m pip install -U pip poetry
       - run: poetry --version
       - run: poetry install