Bump next from 14.2.21 to 15.1.2

Bumps [next](https://github.com/vercel/next.js) from 14.2.21 to 15.1.2.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v14.2.21...v15.1.2)

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

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

package.json

@@ -31,7 +31,7 @@
     "framer-motion": "^11.2.10",
     "github-slugger": "^2.0.0",
     "gray-matter": "^4.0.0",
-    "next": "^14.2",
+    "next": "^15.1",
     "postcss": "^8.4.38",
     "postcss-import": "^16.1.0",
     "react": "^18.2.0",