chore(ci): update to actions/checkout@v4

Author: tottoto

.github/workflows/CI.yml

@@ -218,7 +218,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install Rust
         uses: dtolnay/rust-toolchain@master