Remove visual review app feature flag

This is the CE backport for
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14958

Now that we are confident with the visual review
app link being there, we are removing the
feature flag entirely.

app/assets/javascripts/vue_merge_request_widget/components/mr_widget_pipeline_container.vue

@@ -60,7 +60,7 @@ export default {
       return this.isPostMerge ? this.mr.mergePipeline : this.mr.pipeline;
     },
     showVisualReviewAppLink() {
-      return Boolean(this.mr.visualReviewFF && this.mr.visualReviewAppAvailable);
+      return this.mr.visualReviewAppAvailable;
     },
     showMergeTrainInfo() {
       return _.isNumber(this.mr.mergeTrainIndex);