Add auditor access for group compliance report

What does this MR do and why?

Describe in detail what your merge request does and why.

Closes #355500 (closed)

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auditor-enable-group-compliance-report

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Switch to the master branch and visit GitLab in your browser. Login as an admin user and attempt to visit the compliance report in a group https://gitlab.example.com/groups/<GROUP>/-/security/compliance_dashboard. As an admin, you should be able to view this page.
2. Impersonate an auditor account and attempt to visit https://gitlab.example.com/groups/<GROUP>/-/security/compliance_dashboard. As an auditor, you should see a 404. This is expected.
3. Switch to the auditor-enable-group-compliance-report branch.
4. In the address bar, attempt to visit https://gitlab.example.com/groups/<GROUP>/-/security/compliance_dashboard. As an auditor, you should now be able to view this page.

MR acceptance checklist

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