Prefer linalg::qr over qr in the C++ API (#60529)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/60060
Also adds `torch::linalg::qr` to the C++ API, as it was missing.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60529
Reviewed By: ngimel
Differential Revision: D29353133
Pulled By: mruberry
fbshipit-source-id: e18feaffca91c13940ad3d6bd1f40bb57dc101ae
