fix(deps): update nextjs monorepo to v15

Author: renovate[bot]

package.json

@@ -20,7 +20,7 @@
     "@twilio-paste/icons": "latest",
     "cypress": "7.7.0",
     "fs": "^0.0.1-security",
-    "next": "14.2.25",
+    "next": "15.4.6",
     "prop-types": "15.8.1",
     "react": "18.2.0",
     "react-dom": "18.2.0",
@@ -34,7 +34,7 @@
     "babel-jest": "29.7.0",
     "cypress": "13.17.0",
     "eslint": "8.57.1",
-    "eslint-config-next": "13.5.11",
+    "eslint-config-next": "15.4.6",
     "eslint-config-twilio": "2.0.0",
     "eslint-config-twilio-react": "2.0.0",
     "eslint-plugin-prettier": "4.2.1",