Bug 1824381 [wpt PR 39181] - Update wpt metadata, a=testonly

wpt-pr: 39181
wpt-type: metadata

testing/web-platform/meta/webrtc/protocol/rtp-headerextensions.html.ini

@@ -1,3 +1,6 @@
 [rtp-headerextensions.html]
   [Video orientation header extension is supported.]
     expected: FAIL
+
+  [Negotiates the subset of supported extensions offered]
+    expected: FAIL