feat: Add github_organization_security_configuration and github_enterprise_security_configuration resources

This commit adds two new resources to manage Code Security Configurations:

- `github_organization_security_configuration`: manages code security
  configurations at the organization level
- `github_enterprise_security_configuration`: manages code security
  configurations at the enterprise level

Both resources include:
- Full CRUD operations using GitHub's Code Security Configurations API
- Composite IDs (org/enterprise + config ID) to avoid state collisions
- 404-tolerant delete (treats already-deleted resources as success)
- tflog structured logging throughout
- All optional fields use GetOk to avoid sending unset values
- Custom import support

Acceptance tests (8 total, 4 per resource):
- creates without error
- updates without error
- creates with nested options (runner, autosubmit, bypass)
- creates with minimal config

Documentation added for both resources.

Resolves #2412

Author: sprioriello

github/provider.go

@@ -180,6 +180,7 @@ func Provider() *schema.Provider {
 			"github_organization_role_user":                                         resourceGithubOrganizationRoleUser(),
 			"github_organization_role_team_assignment":                              resourceGithubOrganizationRoleTeamAssignment(),
 			"github_organization_ruleset":                                           resourceGithubOrganizationRuleset(),
+			"github_organization_security_configuration":                            resourceGithubOrganizationSecurityConfiguration(),
 			"github_organization_security_manager":                                  resourceGithubOrganizationSecurityManager(),
 			"github_organization_settings":                                          resourceGithubOrganizationSettings(),
 			"github_organization_webhook":                                           resourceGithubOrganizationWebhook(),
@@ -217,6 +218,7 @@ func Provider() *schema.Provider {
 			"github_enterprise_actions_workflow_permissions":                        resourceGithubEnterpriseActionsWorkflowPermissions(),
 			"github_actions_organization_workflow_permissions":                      resourceGithubActionsOrganizationWorkflowPermissions(),
 			"github_enterprise_security_analysis_settings":                          resourceGithubEnterpriseSecurityAnalysisSettings(),
+			"github_enterprise_security_configuration":                              resourceGithubEnterpriseSecurityConfiguration(),
 			"github_workflow_repository_permissions":                                resourceGithubWorkflowRepositoryPermissions(),
 		},