Bruh Core Zone 2
Fix the issue where custom exits with skipped intermission screens (notably, Black Core Zone 1, 2 and 3) would cause the game to softlock when playing on a save file, or with a live event backup.
The reason this bug happened was because the game requires gameaction to be set to ga_worlddone to progress to the next level, but P_SaveGame sets gameaction to ga_nothing, and that function was getting called after it was set to ga_worlddone.