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

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -9,7 +9,7 @@ jobs:
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
     - name: Set up Python
       uses: actions/setup-python@v5