Hide detection method from the UI

This information is not stored on the backend yet therefore we
are hiding it from the user. It'll be added as soon as the backend
is ready.

ee/app/assets/javascripts/vulnerabilities/components/new_vulnerability/section_details.vue

@@ -147,7 +147,7 @@ export default {
     <gl-form-group
       :label="$options.i18n.detectionMethod.label"
       label-for="form-detection-method"
-      class="gl-mb-6"
+      class="gl-mb-6 gl-display-none"
     >
       <gl-dropdown id="form-detection-method" :text="detectionMethodPlaceholder">
         <gl-dropdown-item