fix(deps): update @mintel/payload-ai to 1.9.18 and migrate patch

package.json

@@ -10,7 +10,7 @@
     "@mintel/next-config": "1.9.11",
     "@mintel/next-feedback": "1.9.11",
     "@mintel/next-utils": "1.9.11",
-    "@mintel/payload-ai": "1.9.17",
+    "@mintel/payload-ai": "1.9.18",
     "@payloadcms/db-postgres": "^3.77.0",
     "@payloadcms/email-nodemailer": "^3.77.0",
     "@payloadcms/next": "^3.77.0",
@@ -176,7 +176,7 @@
       "@mintel/thumbnail-generator": "1.9.11"
     },
     "patchedDependencies": {
-      "@mintel/payload-ai@1.9.17": "patches/@mintel__payload-ai@1.9.17.patch"
+      "@mintel/payload-ai@1.9.18": "patches/@mintel__payload-ai@1.9.18.patch"
     }
   },
   "browserslist": [