Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/hugo.yml

@@ -39,7 +39,7 @@ jobs:
       - name: Install Dart Sass Embedded
         run: sudo snap install dart-sass-embedded
       - name: Checkout
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           submodules: recursive
           fetch-depth: 0