refactor: convert back the checkout version to v4

Author: YifuTao

Diff for: .github/workflows/ruff.yml

@@ -4,7 +4,7 @@ jobs:
   ruff:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: astral-sh/ruff-action@v3
         with:
           version: "0.11.4"