feat(templates): use poetry2nix for template

templates/python/.envrc

@@ -1,6 +1 @@
 use nix
-export PYTHONPATH="$(pwd)/src:$PYTHONPATH"
-if [ ! -z $NIX_LD ]; then
-  export LD_LIBRARY_PATH=$NIX_LD_LIBRARY_PATH
-fi
-layout poetry

templates/python/shell.nix

@@ -1,5 +1,14 @@
 { pkgs ? import <nixpkgs> { } }:
 
+let
+  poetry2nix = import (fetchTarball "https://github.com/nix-community/poetry2nix/archive/master.tar.gz") { };
+  project =
+    poetry2nix.mkPoetryApplication {
+      projectDir = ./.;
+      preferWheels = true;
+    };
+in
 pkgs.mkShell {
-  buildInputs = with pkgs; [ python3 poetry ];
+  inputsFrom = [ project ];
+  packages = [ pkgs.poetry ];
 }