Refactor code structure for improved readability and maintainability

Signed-off-by: Frost Ming <me@frostming.com>

Author: frostming

.github/workflows/ci.yml

@@ -16,14 +16,11 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v5
-        with:
-          python-version: ${{ matrix.python-version }}
-          allow-prereleases: true
-          cache: "pip"
+
       - name: Setup PDM
         uses: pdm-project/setup-pdm@v4
+        with:
+          python-version: ${{ matrix.python-version }}
       - name: Install Dependencies
         run: pdm sync
       - name: Install Mercurial