fix: end TransportConnect profiler marker on early returns in ConnectEventHandler (#4005)

BeginSample was called at the top of ConnectEventHandler but two early
return paths (duplicate server transport ID and duplicate client connect
event) exited without calling EndSample, causing the 'Missing
Profiler.EndSample' error surfaced by the MultipleConnectMessagesNoop
playmode tests.

Author: mnachury-unity

com.unity.netcode.gameobjects/Runtime/Connection/NetworkConnectionManager.cs

@@ -522,6 +522,9 @@ internal void ConnectEventHandler(ulong transportId)
                     {
                         NetworkLog.LogError($"[TransportApproval][Server] TransportId {transportId} is already connected to this server!");
                     }
+#if DEVELOPMENT_BUILD || UNITY_EDITOR
+                    s_TransportConnect.End();
+#endif
                     return;
                 }
 
@@ -536,6 +539,9 @@ internal void ConnectEventHandler(ulong transportId)
                     {
                         NetworkLog.LogError("[TransportApproval][Client] Client received a transport connection event after already connecting!");
                     }
+#if DEVELOPMENT_BUILD || UNITY_EDITOR
+                    s_TransportConnect.End();
+#endif
                     return;
                 }