Remove leftover UNSUBSCRIBE message code.

PiperOrigin-RevId: 972614717

quiche/quic/moqt/moqt_messages.cc

diff --git a/quiche/quic/moqt/moqt_messages.cc b/quiche/quic/moqt/moqt_messages.cc
index c331e4f..ab5e89d 100644
--- a/quiche/quic/moqt/moqt_messages.cc
+++ b/quiche/quic/moqt/moqt_messages.cc
@@ -79,8 +79,6 @@
       return "SUBSCRIBE_OK";
     case MoqtMessageType::kRequestError:
       return "REQUEST_ERROR";
-    case MoqtMessageType::kUnsubscribe:
-      return "UNSUBSCRIBE";
     case MoqtMessageType::kPublishDone:
       return "PUBLISH_DONE";
     case MoqtMessageType::kRequestUpdate:

quiche/quic/moqt/moqt_messages.h

diff --git a/quiche/quic/moqt/moqt_messages.h b/quiche/quic/moqt/moqt_messages.h
index f79dc04..2d35300 100644
--- a/quiche/quic/moqt/moqt_messages.h
+++ b/quiche/quic/moqt/moqt_messages.h
@@ -206,7 +206,6 @@
   kPublishNamespace = 0x06,
   kRequestOk = 0x07,
   kNamespace = 0x08,
-  kUnsubscribe = 0x0a,
   kPublishDone = 0x0b,
   kTrackStatus = 0x0d,
   kNamespaceDone = 0x0e,