Upgrade github actions to v4

As Node.js 16 actions are deprecated, use the latest github actions v4
for  Node.js 20

.github/workflows/main.yml

@@ -11,7 +11,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Build
       working-directory: ${{runner.workspace}}/
       shell: bash