feat(repository): add new check repository_denies_branch_deletion

[HugoPBrito]

Context

Allowing users to delete protected branches poses a risk of accidental or intentional data loss, potentially disrupting workflows or losing critical history in the repository. Preventing branch deletions ensures that the integrity and availability of important branches, such as the main branch, are preserved.

Description

This check ensures that branch deletions are denied on protected branches by verifying that the Allow deletions option is disabled in branch protection rules. Enforcing this rule prevents users with push access from removing critical branches, maintaining the stability and continuity of the repository.

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.