'Something went wrong while loading emojis' on every page on staging

I'm getting this banner on every page of staging:

The error in the console is:

Access to XMLHttpRequest at 'https://gl-staging-canary.freetls.fastly.net/-/emojis/1/emojis.json' from origin 'https://staging.gitlab.com' has been blocked by CORS policy: Request header field x-requested-with is not allowed by Access-Control-Allow-Headers in preflight response.

I'm not sure if this is just a staging thing, or if it will also break in production. cc @timzallmann @iamphill