build(deps): update actions/setup-python action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -140,7 +140,7 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Install Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: "3.14"