Remove actions/setup-python step and enable-cache option from CI workflow

.github/workflows/main.yml

@@ -18,16 +18,9 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Set up Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: "3.14"
-
       - name: Install uv
         id: setup-uv
         uses: astral-sh/setup-uv@v4
-        with:
-          enable-cache: true
 
       - name: Install dependencies
         run: uv sync --all-groups -U