Bug: BarrelList.insert raises IndexError for very negative indices instead of inserting at the beginning

Bug: BarrelList.insert raises IndexError for very negative indices instead of inserting at the beginning: a task in Repo2RLEnv R2E-Gym / SWEGEN (Harbor dataset). When calling insert on a BarrelList with a very negative index (e.g., -1000000000 ), it raises an IndexError instead of inserting at…