feat(repository): add new check repository_enforces_admin_branch_protection

[HugoPBrito]

Context

Branch protection rules are designed to prevent unauthorized or unverified changes to critical branches like the main branch. By default, administrators are exempt from these rules, which can undermine their effectiveness. Since administrator accounts often have elevated privileges and are potential targets for attacks, ensuring that branch protection rules apply to administrators helps safeguard the integrity of the repository.

Description

This check ensures that branch protection rules are enforced for administrators. It validates that even users with elevated privileges must adhere to the same safeguards as other contributors, such as requiring reviews, passing checks, and restrictions on direct pushes. This policy reduces the risk of accidental or malicious changes bypassing established protections.

Checklist

• Are there new checks included in this PR? Yes.
  • If so, do we need to update permissions for the provider? No.
• Review if the code is being covered by tests.
• Review if code is being documented following this specification https://github.com/google/styleguide/blob/gh-pages/pyguide.md#38-comments-and-docstrings
• Review if backport is needed.

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.