task: delete the move constructor for TaskState

Move-constructing isn't good for that class either.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>

lib/task.cc

@@ -89,6 +89,7 @@ namespace crucible {
 
 		TaskState &operator=(const TaskState &) = delete;
 		TaskState(const TaskState &) = delete;
+		TaskState(TaskState &&) = delete;
 
 	public:
 		~TaskState();