Allow project admin to read approval rules when project is archived

What does this MR do?

When a project is archived, you can't create MRs in the project. Permission create_merge_request_in was being checked to determine if the approval rules can be read. A project admin can edit those rules - they should be allowed to read them as well.

This MR allows a user with admin_project permissions to read the approval rules.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

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• Documentation (if required)
• Code review guidelines
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• Style guides
• Database guides
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Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

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• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #27934 (closed)