Prefer mT and mH over transpose(-2, -1) and transpose(-2, -1).conj()
This PR replaces all the calls to `transpose(-2, -1)` and to
`transpose(-2, -1).conj()` or `conj().transpose(-2, -1)` by calls to
`mT` and `mH` on Python and `mT()` and `mH()` on C++
It also simplifies two pieces of code, and fixes one bug where a pair
of parentheses were missing in the function `make_symmetric_matrices`.
ghstack-source-id: f782e2d97b7f36176db91376f7f3f5730341ba8d
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64181
