#37021 exposed that our tests are trying to load a local file path for
Ahem.ttf, but this stops working when we implement the specified CORS
protections for our font requests. Luckily, the WPT suite already
provides a same-origin version of the same font, so we can just update
our CSS to use that font face instead.
Testing: Existing WPT coverage.
Signed-off-by: Josh Matthews <josh@joshmatthews.net>
