Add MANIFEST.in (#52908)
Summary:
Do not build PyTorch if `setup.py` is called with 'sdist' option
Regenerate bundled license while sdist package is being built
Refactor `check_submodules` out of `build_deps` and check that submodules project are present during source package build stage.
Test that sdist package is configurable during `asan-build` step
Fixes https://github.com/pytorch/pytorch/issues/52843
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52908
Reviewed By: walterddr
Differential Revision: D26685176
Pulled By: malfet
fbshipit-source-id: 972a40ae36e194c0b4e0fc31c5e1af1e7a815185
