tests: Use Ahem font provided by WPT harness. (#37054)

#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>

tests/wpt/meta/css/css-align/blocks/align-content-block-002.html.ini

@@ -28,4 +28,3 @@
 
   [.test 16: space-around]
     expected: FAIL
-    

tests/wpt/mozilla/meta/MANIFEST.json

@@ -8608,7 +8608,7 @@
     ],
     "css": {
      "ahem.css": [
-      "51eede74aaa0b43f2c9235019bc73a508b1f14e4",
+      "a7db592e0df53e0b70f66ca7b31a7734db18887e",
       []
      ]
     },
@@ -10654,7 +10654,7 @@
       []
      ],
      "no_mime_type.py": [
-      "860005a42c237735287031133786352d7c732402",
+      "980eeee18f993f20a9df033f337a52ec93155ec4",
       []
      ],
      "origin_helpers.js": [

tests/wpt/mozilla/tests/css/css/ahem.css

@@ -1,3 +1,9 @@
+@font-face {
+    font-family: 'ahem';
+    src: local('Ahem'),
+         url('/fonts/Ahem.ttf');
+}
+
 body {
     font-family: 'ahem';
     font-size: 100px;

tests/wpt/mozilla/tests/mozilla/resources/no_mime_type.py

@@ -7,5 +7,5 @@ def main(request, response):
     headers = []
     if b'Content-Type' in request.GET:
         headers += [(b'Content-Type', request.GET[b'Content-Type'])]
-    with open('./resources/ahem/AHEM____.TTF', 'rb') as f:
+    with open('./tests/wpt/tests/fonts/Ahem.ttf', 'rb') as f:
         return 200, headers, f.read()