chore: update to 15.2.3

Author: joshblack

examples/nextjs/package.json

@@ -11,7 +11,7 @@
   },
   "dependencies": {
     "@primer/react": "37.17.0",
-    "next": "^14.2.25",
+    "next": "^15.2.3",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
     "styled-components": "5.x",