Change update-a2a-types to run when generate_types.sh is edited

Author: holtskinner

.github/workflows/update-a2a-types.yml

@@ -4,6 +4,15 @@ on:
   repository_dispatch:
     types: [a2a_json_update]
   workflow_dispatch:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - "scripts/generate_types.sh"
+    types:
+      - opened
+      - synchronize
+      - reopened
 
 jobs:
   generate_and_pr: