Add table github_organization_ruleset

[romain-pix-cyber]

Problem : Steampipe allows to query the ruleset from individual repositories but not rulesets defined at the organization level.

This PR solves the issue with a new table github_organization_ruleset :

• New table mirrors github_repository_ruleset but scoped to an organization via
  organization(login: $org) GraphQL path
• Reuses existing Rule, BypassActor, Conditions models
• Includes docs at docs/tables/github_organization_ruleset.md

Example query results

Details

select
  name,
  enforcement,
  created_at
from
  github_organization_ruleset
where
  organization = 'my-org';

Results

+--------------------+-------------+---------------------------+
| name               | enforcement | created_at                |
+--------------------+-------------+---------------------------+
| Corp-Rule-Infra    | EVALUATE    | 2026-02-06T10:47:41+01:00 |
| Branche protection | DISABLED    | 2025-07-18T11:38:12+02:00 |
+--------------------+-------------+---------------------------+

I used AI to generate most of the code following the documentation, then reviewed and verified manually the compilation and the results.