Update actions/checkout action to v6.0.3

Author: renovate[bot]

.github/workflows/style.yaml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
     - name: Checkout
-      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
     - name: prek
       uses: glotzerlab/workflows/prek@204dc7c0f82720090703712694b7cab761aacaa0 # 0.13.0