update next version in playgrounds

Author: chenxzhang

playgrounds/next-playground/package.json

@@ -16,7 +16,7 @@
     "@segment/analytics-next": "workspace:^",
     "faker": "^5.1.0",
     "lodash": "^4.17.21",
-    "next": "^12.1.0",
+    "next": "^12.3.5",
     "prismjs": "^1.27.0",
     "rc-table": "^7.10.0",
     "react": "^17.0.2",