fix(dashboard): Set correct method value on promotion (#9610)

<img width="1441" alt="Screenshot 2024-10-16 at 14 17 05" src="https://github.com/user-attachments/assets/7a2e2196-5ca6-4532-9bf0-a4b693c6babc">

RESOLVES CC-601

packages/admin/dashboard/src/i18n/translations/en.json

@@ -1716,6 +1716,7 @@
       "value_type": "Value Type",
       "value": "Value",
       "campaign": "Campaign",
+      "method": "Method",
       "allocation": "Allocation",
       "addCondition": "Add condition",
       "clearAll": "Clear all",