Downgrade setuptools from 82.0.0 to 81.0.0

The package pkg_resources is required by mkdocs but has been removed from latest 82.0.0 version of setuptools, therefore we need to downgrade to use 81.0.0 version of setuptools.

Author: uvindra

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
       - run: |
           echo "Installing Python dependencies"
           pip install --upgrade pip  # Ensure pip is up-to-date
-          pip install setuptools==82.0.0
+          pip install setuptools==81.0.0
           pip install zipp==3.0.0
           pip install pathlib2==2.3.5
           pip install -U --upgrade mkdocs==1.4.2