Update interfaces/webauthn.idl (#23626)

Source: https://github.com/tidoust/reffy-reports/blob/8de5e63/ed/idl/webauthn.idl
Build: https://travis-ci.org/tidoust/reffy-reports/builds/687251575
diff --git a/interfaces/webauthn.idl b/interfaces/webauthn.idl
index 73c96c8..a1d46a3 100644
--- a/interfaces/webauthn.idl
+++ b/interfaces/webauthn.idl
@@ -31,6 +31,9 @@
 interface AuthenticatorAttestationResponse : AuthenticatorResponse {
     [SameObject] readonly attribute ArrayBuffer      attestationObject;
     sequence<DOMString>                              getTransports();
+    ArrayBuffer                                      getAuthenticatorData();
+    ArrayBuffer?                                     getPublicKey();
+    COSEAlgorithmIdentifier                          getPublicKeyAlgorithm();
 };
 
 [SecureContext, Exposed=Window]