Move read_prometheus_alerts into maintainer_access

Move read_prometheus_alerts policy into exising maintainer_access block

app/policies/project_policy.rb

@@ -316,6 +316,7 @@ class ProjectPolicy < BasePolicy
     enable :create_deploy_token
     enable :read_pod_logs
     enable :destroy_deploy_token
+    enable :read_prometheus_alerts
   end
 
   rule { (mirror_available & can?(:admin_project)) | admin }.enable :admin_remote_mirror
@@ -445,8 +446,6 @@ class ProjectPolicy < BasePolicy
     (can?(:read_project_for_iids) & issues_visible_to_user) | can?(:read_issue)
   end.enable :read_issue_iid
 
-  rule { can?(:maintainer_access) }.enable :read_prometheus_alerts
-
   rule do
     (~guest & can?(:read_project_for_iids) & merge_requests_visible_to_user) | can?(:read_merge_request)
   end.enable :read_merge_request_iid