feat: add enterprise (inherited) runner group org setting resource

This resource allows managing organization-level settings for enterprise
Actions runner groups that are inherited by an organization. It configures
various org-specific settings such as allowed repositories, visibility and
workflow restrictions. The existing org-level resource assumes that an
organization runner group is to be created & fully managed by Terraform so
it does not work for an enterprise-scope group that is shared with one or
more organizations within a GitHub Enterprise environment.

Closes #2768

Author: coopernetes

github/provider.go

@@ -213,6 +213,7 @@ func Provider() *schema.Provider {
 			"github_enterprise_actions_runner_group":                                resourceGithubActionsEnterpriseRunnerGroup(),
 			"github_enterprise_actions_workflow_permissions":                        resourceGithubEnterpriseActionsWorkflowPermissions(),
 			"github_actions_organization_workflow_permissions":                      resourceGithubActionsOrganizationWorkflowPermissions(),
+			"github_enterprise_actions_runner_group_org_settings":                   resourceGithubEnterpriseActionsRunnerGroupOrgSettings(),
 			"github_enterprise_security_analysis_settings":                          resourceGithubEnterpriseSecurityAnalysisSettings(),
 			"github_workflow_repository_permissions":                                resourceGithubWorkflowRepositoryPermissions(),
 		},