Update vulnerability-scanner.yaml - improve naming

Author: tungbq

.github/workflows/vulnerability-scanner.yaml

@@ -1,11 +1,11 @@
-name: build
+name: Scans container images
 on:
   schedule:
     - cron: '0 0 */14 * 6' # Run every 14 days on Saturday at midnight
   workflow_dispatch:
 jobs:
   build:
-    name: Build
+    name: Scan
     runs-on: ubuntu-24.04
     steps:
       - name: Run Trivy vulnerability scanner