Use built-in without_status scope

Use built-in into a state machine `without_status` scope
in `AlertManagement::Alert.not_resolved`

app/models/alert_management/alert.rb

@@ -126,7 +126,7 @@ module AlertManagement
     scope :for_environment, -> (environment) { where(environment: environment) }
     scope :search, -> (query) { fuzzy_search(query, [:title, :description, :monitoring_tool, :service]) }
     scope :open, -> { with_status(OPEN_STATUSES) }
-    scope :not_resolved, -> { where.not(status: STATUSES[:resolved]) }
+    scope :not_resolved, -> { without_status(:resolved) }
     scope :with_prometheus_alert, -> { includes(:prometheus_alert) }
 
     scope :order_start_time,    -> (sort_order) { order(started_at: sort_order) }