Vendors all its dependencies

Description:

When investigating dependency chains in the context of archlinux/python-bootstrap#2 (closed) I noticed, that this package actually vendors all of its dependencies: https://github.com/python-poetry/poetry-core/tree/main/src/poetry/core/_vendor

To properly devendor, a patch is needed to neither install nor use the vendored dependencies. I have done similar for python-pdm-backend: https://gitlab.archlinux.org/archlinux/packaging/packages/python-pdm-backend/-/blob/a194b824882a3fea50b474f64cf849db5ed8fd5f/python-pdm-backend-2.0.7-devendor.patch

Without patching this package, it otherwise does not depend on the packages it currently depends on.