Bump next from 13.5.4 to 14.1.1 in /frontend (#29)

* Bump next from 13.5.4 to 14.1.1 in /frontend

Bumps [next](https://github.com/vercel/next.js) from 13.5.4 to 14.1.1.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v13.5.4...v14.1.1)

---
updated-dependencies:
- dependency-name: next
  dependency-type: direct:production
...

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

* update snapshot

* fix

* update snapshot

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Masashi Tomooka <tmokmss@users.noreply.github.com>

frontend/next.config.js

@@ -2,6 +2,7 @@
 const nextConfig = {
  reactStrictMode: true,
  swcMinify: true,
+ output: 'export',
  webpack: (config, options) => {
  config.externals.push('mapbox-gl');
  return config;