Fix outdated package name

[66RING]

lasync_communication and lightseq_ckpt_monkey_patch.replace_hf_ckpt_with_fast_ckpt not found.

rename to

from async_communication import

and

from lightseq_ckpt_monkey_patch import replace_hf_ckpt_with_new_ckpt, clear_all_buffers_at_the_end_of_training
replace_hf_ckpt_with_new_ckpt()