I merged this a bit too quick. We need to have a closer look at it.
See the points brought up in https://github.com/NixOS/nixpkgs/pull/64682.
This reverts commit 1e0ebdb8a4fe94db67b6520225d325292d60247c.
This changeset allows for cross-compilation of Python packages. Packages
built with buildPythonPackage are not allowed to refer to the build
machine. Executables that have shebangs will refer to the host.