Bump next from 14.2.22 to 15.2.1

Bumps [next](https://github.com/vercel/next.js) from 14.2.22 to 15.2.1.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v14.2.22...v15.2.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -14,7 +14,7 @@
   "dependencies": {
     "add": "^2.0.6",
     "autoprefixer": "^10.4.20",
-    "next": "^14.2.22",
+    "next": "^15.2.1",
     "next-sitemap": "^4.2.3",
     "nextra": "^3.2.4",
     "nextra-theme-docs": "^3.2.4",