edit workflow

Author: beran-t

.github/workflows/api-reference-validation.yml

@@ -4,7 +4,10 @@ on:
   # schedule:
   #   # Every Thursday at 8 PM UTC
   #   - cron: '0 20 * * 4'
-  workflow_dispatch:
+  pull_request:
+    # Sequence of patterns matched against refs/heads
+    branches:
+      - main
 
 concurrency:
   group: api-reference-validation