Change schedule to 6AM PT 13 UTC on every Monday (#2550)

Author: spring1843

.github/workflows/api-code-gen.yml

@@ -2,7 +2,7 @@ name: "APICodeGen"
 
 on:
   schedule:
-    - cron: '0 * * * *'
+    - cron: '0 13 * * MON'
 
 permissions:
   id-token: write