CMake: Limit python include directories to only python libraries (#65654)
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.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65654
Reviewed By: gchanan
Differential Revision: D31193205
Pulled By: malfet
fbshipit-source-id: 5c1b554a59d0e441a701a04ebb62f0032d38b208
