Bump actions/checkout from 3 to 4 (#19)

Author: dependabot[bot]

.github/workflows/build.yml

@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Setup Node
         uses: actions/setup-node@v4
@@ -56,7 +56,7 @@ jobs:
 
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       # Fetch the built HTML from the build job
       - name: Download HTML artifact