Bump next from 15.3.5 to 15.4.7 in /packages/gitbook

Bumps [next](https://github.com/vercel/next.js) from 15.3.5 to 15.4.7. - [Release notes](https://github.com/vercel/next.js/releases) - [Changelog](https://github.com/vercel/next.js/blob/canary/release.js) - [Commits](vercel/next.js@v15.3.5...v15.4.7) --- updated-dependencies: - dependency-name: next dependency-version: 15.4.7 dependency-type: direct:production ... Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

packages/gitbook/package.json

@@ -47,7 +47,7 @@
  "micromark-extension-frontmatter": "^2.0.0",
  "micromark-extension-gfm": "^3.0.0",
  "motion": "^12.23.12",
- "next": "15.4.0",
+ "next": "15.4.7",
  "next-themes": "^0.2.1",
  "nuqs": "^2.2.3",
  "object-hash": "^3.0.0",