Deprecate symeig (#57732)
Summary:
This one had a tricky usage of `torch.symeig` that had to be replaced. I tested the replacement locally though.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57732
Reviewed By: bdhirsh
Differential Revision: D28328189
Pulled By: mruberry
fbshipit-source-id: 7f000fcbf2b029beabc76e5a89ff158b47977474
