Update checkout action version to v6

Signed-off-by: Lee Calcote <leecalcote@gmail.com>

Author: leecalcote

.github/workflows/preview-site.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Download Site dir
         uses: dawidd6/action-download-artifact@v11