#44327 made sure to always run `set_package_py_globals` on all
packages before running `setup_dependent_package` for any package,
so that packages implementing the latter could depend on variables
like `spack_cc` being defined.
This ran into an undocumented dependency: `std_cmake_args` is set in
`set_package_py_globals` and makes use of `cmake_prefix_paths` (if it
is defined in the package); `py-torch`es implementation of
`cmake_prefix_paths` depends on a variable set by
`setup_dependent_package` (`python_platlib`).
This generally restores #44327, and corrects the resulting issue by
moving assignment of `std_cmake_args` to after both actions have been
run.
31cfcafeba