Update CI workflow name and checkout action version

Author: TrainCo

.github/workflows/demo.yml

@@ -1,15 +1,20 @@
-name: CI Workflow
+
+name: CI Workflow Trigger
 
 on:
   push:
     branches:
-        uses: actions/checkout@v3      - main
-
-      - name: Run a sample script
-        run: echo "Build
+      - main
 
 jobs:
   build:
     runs-on: ubuntu-latest
+
     steps:
-      - name: Checkout code
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Verify runner
+        run: |
+          echo "Runner OS: $RUNNER_OS"
+          uname -a