Remove API endpoints being deprecated in 3.8 (#5880)

i18n/en.json

@@ -79,6 +79,10 @@
     "id": "api.admin.get_brand_image.storage.app_error",
     "translation": "Image storage is not configured."
   },
+  {
+    "id": "api.deprecated.init.debug",
+    "translation": "Initializing deprecated API routes"
+  },
   {
     "id": "api.admin.init.debug",
     "translation": "Initializing admin API routes"