[FEAT]: Add Support for GitHub Enterprise Rulesets

[nelsonfigueroa]

Describe the need

Currently, the Terraform GitHub provider supports organization rulesets and repository rulesets. However, there is no support for rulesets at the enterprise level which GitHub supports on its UI (if you're on the Enterprise plan).

More information around rulesets:

• About rulesets
• Managing code rulesets for repositories in your enterprise

Code of Conduct

• [x] I agree to follow this project's Code of Conduct