Use confirm variant for 'New requirement' button

Changelog: changed
EE: true

ee/app/assets/javascripts/requirements/components/requirements_empty_state.vue

@@ -53,7 +53,7 @@ export default {
       :description="emptyStateDescription"
     >
       <template v-if="emptyStateDescription && canCreateRequirement" #actions>
-        <gl-button category="primary" variant="success" @click="$emit('click-new-requirement')">{{
+        <gl-button category="primary" variant="confirm" @click="$emit('click-new-requirement')">{{
           __('New requirement')
         }}</gl-button>
         <gl-button

ee/app/assets/javascripts/requirements/components/requirements_tabs.vue

@@ -112,7 +112,7 @@ export default {
 
       <gl-button
         category="primary"
-        variant="success"
+        variant="confirm"
         class="js-new-requirement qa-new-requirement-button"
         :disabled="showCreateForm"
         @click="$emit('click-new-requirement')"