feat(repository): add new check repository_enforces_default_branch_protection

[HugoPBrito]

Context

The default or main branch of a repository often represents the production-ready code and is critical to the stability and security of the project. Protecting this branch from unauthorized or unreviewed changes is essential to maintain the integrity of the codebase. Enforcing branch protection rules ensures that only approved changes, with proper testing and review, are merged into the main branch, preventing potential vulnerabilities from being introduced into production.

Description

This check ensures that branch protection is enforced on the default or main branch of a repository. By setting up branch protection rules, it restricts who can push changes directly, requires reviews and approvals before merging, and enforces necessary tests or checks, safeguarding the code from unapproved changes that could compromise the project's stability.

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.