CMake: Limit python include directories to only python libraries (#69085)
Summary:
`include_directories` is old-style CMake which adds the include path to every file being compiled. This instead makes `python`, `numpy` and `pybind11` into targets that only `torch_python` and `caffe2_pybind_state` are linked to. So, python libraries can't be accidentally included elsewhere.
Resubmit of https://github.com/pytorch/pytorch/issues/65654, Closes https://github.com/pytorch/pytorch/issues/65828
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69085
Reviewed By: anjali411
Differential Revision: D33776456
Pulled By: malfet
fbshipit-source-id: 018b0f6cd5a4f8c9e36df961deff832bc4afd479
(cherry picked from commit 57063107d65a0377dba9ef86fedd056f6ae05f21)
