github actions: use actions/checkout@v4

Fixes:
Node.js 16 actions are deprecated. Please update the following actions to use Node.js 20: actions/checkout@v3. For more information see: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/.

.github/workflows/build.yml

@@ -26,7 +26,7 @@ jobs:
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job
       # can access it
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: setup prerequisites
         shell: bash