feat: Customizable webhook timeout configuration (#12777)

## Summary
- Ability to configure the webhook timeout for Chatwoot self hosted
installations

fixes: https://github.com/chatwoot/chatwoot/issues/12754

app/controllers/super_admin/app_configs_controller.rb

@@ -47,7 +47,7 @@ class SuperAdmin::AppConfigsController < SuperAdmin::ApplicationController
 
     @allowed_configs = mapping.fetch(
       @config,
-      %w[ENABLE_ACCOUNT_SIGNUP FIREBASE_PROJECT_ID FIREBASE_CREDENTIALS MAXIMUM_FILE_UPLOAD_SIZE]
+      %w[ENABLE_ACCOUNT_SIGNUP FIREBASE_PROJECT_ID FIREBASE_CREDENTIALS WEBHOOK_TIMEOUT MAXIMUM_FILE_UPLOAD_SIZE]
     )
   end
 end