Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -43,7 +43,7 @@ jobs:
     timeout-minutes: 5
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Check libs