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

Author: renovate-bot

.github/workflows/style.yaml

@@ -13,7 +13,7 @@ jobs:
     steps:
       - name: install cmake-format
         run: pip install cmakelang==0.6.13
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: clang-format
         run: git ls-files -z | grep -zE '\.(cc|h)$' | xargs -P 2 -n 50 -0 clang-format -i
       - name: cmake-format