Fix shebang in manage.py

manage.py

@@ -1,4 +1,4 @@
-#!/nix/store/32q6ryrb860sksdi1al5djg3pgcpq92l-python3-3.8.11/bin/python
+#!/usr/bin/env python3
 """Django's command-line utility for administrative tasks."""
 import os
 import sys

shell.nix

@@ -1,19 +0,0 @@
-let
-  pkgs = import <nixpkgs> {};
-in pkgs.mkShell {
-  buildInputs = with pkgs; [
-    python3
-    python3.pkgs.django
-    python3.pkgs.pip
-    python3.pkgs.pillow
-  ];
-  shellHook = ''
-    # Tells pip to put packages into $PIP_PREFIX instead of the usual locations.
-    # See https://pip.pypa.io/en/stable/user_guide/#environment-variables.
-    export PIP_PREFIX=$(pwd)/_build/pip_packages
-    export PYTHONPATH="$PIP_PREFIX/${pkgs.python3.sitePackages}:$PYTHONPATH"
-    export PATH="$PIP_PREFIX/bin:$PATH"
-    unset SOURCE_DATE_EPOCH
-  '';
-}
-