Hiding the tag-info button for non-admins

I can reproduce this bug here on meta on unsupported-install, there’s a link to /tag_groups that returns a 404.

That said, I did hide this button for non-staff users in my community just to avoid the clutter:

body:not(.staff) #show-tag-info {
  display: none;
}

You don’t need to

I do this kind of tweak as a theme component, use the ➕Install button below the list of theme components and Create new, customize the CSS and add it to the themes you want.