DX-2361: Run external link check on every pull request

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sharadregoti

.github/workflows/check-external-links.yml

@@ -1,9 +1,7 @@
 name: Check External Links
 
 on:
-  schedule:
-    # Runs every Monday at 07:00 UTC
-    - cron: '0 7 * * 1'
+  pull_request:
   workflow_dispatch:
     inputs:
       timeout: