Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -15,7 +15,7 @@ jobs:
   checkov:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3.0.2
+      - uses: actions/checkout@v6.0.1
 
       - name: Get checkov
         run: pip install checkov