destroy metrics endpoint

app/controllers/projects/prometheus/metrics_controller.rb

 module Projects
   module Prometheus
     class MetricsController < Projects::ApplicationController
-      before_action :authorize_read_project!
+      before_action :authorize_admin_project!
       before_action :require_prometheus_metrics!
 
       def active_common
@@ -75,6 +75,13 @@ module Projects
         @metric = project.prometheus_metrics.find(params[:id])
       end
 
+      def destroy
+        @metric = project.prometheus_metrics.find(params[:id])
+        @metric.destroy
+
+        redirect_to project_prometheus_metrics(@project), status: 302
+      end
+
       private
 
       def query_validation_params