Bump next from 10.0.6 to 12.1.0 in /frontend

Bumps [next](https://github.com/vercel/next.js) from 10.0.6 to 12.1.0.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v10.0.6...v12.1.0)

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

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

Author: dependabot[bot]

frontend/package.json

@@ -26,7 +26,7 @@
         "http-proxy-middleware": "^1.0.5",
         "libphonenumber-js": "^1.9.11",
         "lodash": "^4.17.21",
-        "next": "10.0.6",
+        "next": "12.1.0",
         "react": "17.0.1",
         "react-bulma-components": "^4.0.7",
         "react-dom": "17.0.1",