chore(ci): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -26,7 +26,7 @@ jobs:
           egress-policy: audit
 
       - name: Checkout code
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - uses: cachix/install-nix-action@fd24c48048070c1be9acd18c9d369a83f0fe94d7 # v31
         with: