[243] Upgrade next.js

[Regina-Gimazova]

Summary

A brief description of the pull request.

Resolves: #243

Screenshots in case of UI changes

Test plan

List of steps to manually test introduced functionality:

• Go to ReviewApp
• ...

What do need to pay more attention to, some implicit changes that influence the app:

• ...

Review notes

While reviewing pull-request (especially when it's your pull-request), please make sure that:

• you named PR close to issue name and linked that issue
• you understand what problem is solved by PR and how is it solved
• new tests are in place, no redundant tests
• required ENV variables added and described in .env.example and added to Heroku
• associated Heroku review app works correctly with introduced changes