update selector

Author: shahzad31

x-pack/plugins/uptime/e2e/page_objects/monitor_management.tsx

@@ -58,6 +58,7 @@ export function monitorManagementPageProvider({
 
     async deleteMonitor() {
       await this.clickByTestSubj('monitorManagementDeleteMonitor');
+      await this.clickByTestSubj('confirmModalConfirmButton');
       return await this.findByTestSubj('uptimeDeleteMonitorSuccess');
     },