Sidebar search and menu items don't work if you reject optional cookies

The sidebar is non-functional if you reject optional cookies:

Screencast_from_06-10-22_18_39_59

To reproduce:

1. Visit https://design.gitlab.com (from Europe)
2. Reject non-essential cookies
3. Observe broken sidebar

To fix:

1. Clear all cookies for the domain
2. Visit https://design.gitlab.com (from Europe)
3. Accept non-essential cookies
4. Observe working sidebar

Unfortunately there are no logged errors, and (apparently) no failed network requests that would help debug this.