Update dependency @posthog/nextjs-config to ^1.4.0

Author: renovate[bot]

package.json

@@ -33,7 +33,7 @@
     "@date-fns/utc": "^2.1.1",
     "@neondatabase/serverless": "^1.0.2",
     "@opentelemetry/api": "^1.9.0",
-    "@posthog/nextjs-config": "^1.3.10",
+    "@posthog/nextjs-config": "^1.4.0",
     "@readme/http-status-codes": "^9.0.5",
     "@sparticuz/chromium": "141.0.0",
     "@tanstack/react-query": "^5.90.7",