Change variant to confirm

Changelog: changed

app/assets/javascripts/members/components/action_buttons/approve_access_request_button.vue

@@ -40,7 +40,7 @@ export default {
       :title="$options.title"
       :aria-label="$options.title"
       icon="check"
-      variant="success"
+      variant="confirm"
       type="submit"
     />
   </gl-form>