Maximum size for GitLab pages doesn't accept a value of 0

Summary

Go to Admin Area -> Settings -> Preference -> Pages

It currently shows 0 for unlimited.

Setting it to 0 would show Max pages size must be greater than 0.

What is the expected correct behavior?

Allow setting 0 on the backend

Need to change greater_than: to greater_than_or_equal_to in a ee/app/model/ee/project.rb / ee/app/model/ee/namespace.rb and fix related tests

Customer info

Encountered while trying to solve a different issue: https://gitlab.zendesk.com/agent/tickets/144977