python3Packages.twine: rely on importlib-metadata unconditionally
python3Packages.twine: rely on importlib-metadata unconditionally

Changed from conditional to unconditional in
https://github.com/pypa/twine/commit/22aaa04a88780cfc67fc0e5b80eab9784e81c982

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs