* stage 1: should work with non-editable pytorch

Signed-off-by: Masaki Kozuki <mkozuki@nvidia.com>

* update

Signed-off-by: Masaki Kozuki <mkozuki@nvidia.com>

* `build_meta` looks okay, no need to fall back to `build_meta.__legacy__`

Signed-off-by: Masaki Kozuki <mkozuki@nvidia.com>

* cosmetic

Signed-off-by: Masaki Kozuki <mkozuki@nvidia.com>

* Update README.md

* Update README.md

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Signed-off-by: Masaki Kozuki <mkozuki@nvidia.com>