Add pagination to protected environments

What does this MR do and why?

The API returns the first 20 protected environments by default. We need to handle pagination to get all the protected environment data.

Screenshots or screen recordings

How to set up and validate locally

1. Visit the Environments page:
   • Project -> Operate -> Environments if the new navigation is enabled
   • Project -> Deployments -> Environments if the new navigation is not enabled
2. Create a bunch of environments (at least 21)
3. Go to Settings -> CI/CD -> Protected Environments
4. Protect at least 21 environments to see the pagination

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Review progress:

• UX review
• frontend developer review
• frontend maintainer review

Related to #411545 (closed)