[legacy] move communication and nn to legacy and refactor logger (#4671)

* [legacy] move communication to legacy (#4640)

* [legacy] refactor logger and clean up legacy codes (#4654)

* [legacy] make logger independent to gpc

* [legacy] make optim independent to registry

* [legacy] move test engine to legacy

* [legacy] move nn to legacy (#4656)

* [legacy] move nn to legacy

* [checkpointio] fix save hf config

* [test] remove useledd rpc pp test

* [legacy] fix nn init

* [example] skip tutorial hybriad parallel example

* [devops] test doc check

* [devops] test doc check

colossalai/nn/lr_scheduler/linear.py

@@ -1,9 +1,6 @@
 from torch.optim.lr_scheduler import _LRScheduler
 
-from colossalai.legacy.registry import LR_SCHEDULERS
 
-
-@LR_SCHEDULERS.register_module
 class LinearWarmupLR(_LRScheduler):
     """Linearly warmup learning rate and then linearly decay.