remove setCodecPreferences note already covered by JSEP

fixes #2933

webrtc.html

@@ -11250,17 +11250,6 @@ <h2>
                   where <var>kind</var> is the kind of the
                   {{RTCRtpTransceiver}} on which the method is called.
                 </p>
-                <p class="note">
-                  Due to a recommendation in [[!SDP]], calls to
-                  {{RTCPeerConnection/createAnswer}} SHOULD use only the common
-                  subset of the codec preferences and the codecs that appear in
-                  the offer. For example, if codec preferences are "C, B, A",
-                  but only codecs "A, B" were offered, the answer should only
-                  contain codecs "B, A". However, <span data-jsep=
-                  "initial-answers">[[!RFC8829]]</span> allows adding codecs that
-                  were not in the offer, so implementations can behave
-                  differently.
-                </p>
                 <p>
                   When {{setCodecPreferences()}} is invoked, the <a>user
                   agent</a> MUST run the following steps: