Deprecate torch.cholesky (#57725)
Summary:
**BC-breaking note:**
This PR deprecates torch.cholesky in favor of torch.linalg.cholesky. A upgrade guide is added to the documentation for torch.cholesky.
Note this PR DOES NOT remove torch.cholesky.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57725
Reviewed By: bdhirsh
Differential Revision: D28318260
Pulled By: mruberry
fbshipit-source-id: e7ba049321810e70f4de08e6ac37ff800e576152
