chore: fix API ref generator to run on push to master (#2787)

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

@@ -1,5 +1,12 @@
 name: Generate API Reference
 on: 
+  push:
+    branches:
+      - "master"
+    paths:
+      - packages/medusa/src/api/routes/**
+      - '!packages/medusa/src/api/routes/**/index.ts'
+      - '!packages/medusa/src/api/routes/**/index.js'
   pull_request:
     types:
       - closed