chore(deps): update actions/checkout action to v6 (#296)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/docs.yml

@@ -18,7 +18,7 @@ jobs:
         concurrency:
             group: ${{ github.workflow }}
         steps:
-            - uses: actions/checkout@v4
+            - uses: actions/checkout@v6
               with:
                   fetch-depth: 0