Make torch.linalg.eigvalsh differentiable (#57189)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57189
`torch.linalg.eigvalsh` now supports autograd. This is achieved by
computing the eigenvectors internally if input requires grad,
otherwise the eigenvectors are not computed and the operation is faster.
Test Plan: Imported from OSS
Reviewed By: mrshenli
Differential Revision: D28199708
Pulled By: albanD
fbshipit-source-id: 12ac56f50137398613e186abd49f82c8ab83532e
