ci: bump checkout action version

Author: Athemis

.github/workflows/release.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Cache cargo
         uses: actions/cache@v4
@@ -67,7 +67,7 @@ jobs:
       RUSTFLAGS: -C target-feature=+crt-static
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Install stable toolchain
         uses: dtolnay/rust-toolchain@stable