Only show non-static workflows in delays view filter

classes/local/form/form_delays_filter.php

@@ -51,9 +51,12 @@ class form_delays_filter extends \moodleform {
                 'global' => get_string('globally', 'tool_lifecycle')
         ];
         foreach ($activeworkflows as $activeworkflow) {
+            // Only show non-static workflows.
+            if (workflow_manager::is_disableable($activeworkflow->id)) {
                 $workflowoptions[$activeworkflow->id] = get_string('delays_for_workflow', 'tool_lifecycle',
                     $activeworkflow->displaytitle);
             }
+        }
         $mform->addElement('select', 'workflow', get_string('show_delays', 'tool_lifecycle'), $workflowoptions);
 
         // Use core_course_category for moodle 3.6 and higher.