Update pyshell template to use pyproject-nix

templates

@@ -192,22 +192,21 @@ nix-mode
            "in" n
            > "python3.pkgs.callPackage ./derivation.nix {" q "}")
 (pyshell "let" n
-         > "pkgs = import " (p "<nixpkgs>") " {};" n
+         > "pkgs = import " (p "<nixpkgs>") " { };" n
+         > "pyproject-nix = import (builtins.fetchGit {" n
+         > "url = \"https://github.com/pyproject-nix/pyproject.nix.git\";" n
+         > "}) { inherit (pkgs) lib; };" n
          > "python3 = pkgs." (p "python3") ";" n
-         > "in pkgs.mkShellNoCC {" n
-         > "packages = [" n
-         > "(python3.withPackages(" n
-         > "ps: with ps; ["n
-         > (p "tkinter mypy") n
-         > "]" n
-         > (p "++ (callPackage ./derivation.nix { }).dependencies") n
-         > "))" n
-         > "];" n
+         > "project = pyproject-nix.lib.project.loadPoetryPyproject { projectRoot = ./.; };" n
+         > "pythonEnv = python3.withPackages (project.renderers.withPackages { python = python3; });" n
+         "in" n
+         "pkgs.mkShellNoCC {" n
+         > "packages = [pythonEnv];" n
          > "shellHook = ''" n
-         > "export PYTHONPATH=$(readlink -f " (p "./") "):$PYTHONPATH" n
+         > "export PYTHONPATH=$(readlink -f " (p "./.") "):$PYTHONPATH" n
          > "export MPLBACKEND=" (p "TkAgg") n
          > "'';"n
-         > "}")
+         "}")
 
 (sal > "pkgs.fetchFromGitHub {" n
      > "owner = \"pixelifytica\";" n