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

Author: renovate[bot]

.github/workflows/lint.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup Python
         uses: actions/setup-python@v5