Alerting: Update DbStore to use disabled orgs from the config (#52156)

* update DbStore to use UnifiedAlerting settings
* remove disabled orgs from scheduler and use config in db store instead
* remove test

pkg/services/ngalert/models/alert_rule.go

@@ -316,8 +316,6 @@ type ListAlertRulesQuery struct {
 }
 
 type GetAlertRulesForSchedulingQuery struct {
-	ExcludeOrgIDs []int64
-
 	Result []*SchedulableAlertRule
 }