Fix not being able to spectate users in daily challenge gameplay (ppy#37781)

Addresses ppy#37714.

Author: peppy

osu.Game/Overlays/Dashboard/CurrentlyOnline/RealtimeUserList.cs

@@ -178,6 +178,7 @@ private static void updateUserSpectateState(UserPresence presence, OnlineUserPan
                     break;
 
                 case UserActivity.InSoloGame:
+                case UserActivity.PlayingDailyChallenge:
                 case UserActivity.InMultiplayerGame:
                 case UserActivity.InPlaylistGame:
                     userPanel.CanSpectate.Value = true;