[sparsity] Lambda Scheduler (#59771)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59771
Implements a specific sparsity scheduler, that uses a user-provided lambda's to change the levels.
Test Plan:
```
python test/test_ao_sparsity.py
```
Imported from OSS
Differential Revision:
D29070604
D29070604
Reviewed By: raghuramank100
Pulled By: z-a-f
fbshipit-source-id: c7ccbe63fe4cd6a0c3563541b7fcf93a99d0e62f
