build(deps): bump next from 14.2.30 to 15.4.2

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.4.2
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package.json

@@ -30,7 +30,7 @@
     "framer-motion": "^12.0.0",
     "md5": "^2.3.0",
     "multer": "^2.0.0",
-    "next": "^14.1.0",
+    "next": "^15.4.2",
     "next-auth": "^4.24.11",
     "next-connect": "^1.0.0",
     "next-secure-headers": "^2.2.0",