google-cloud-sdk: remove from python-modules

It is not a python module just an application using/based on python.

pkgs/tools/admin/google-cloud-sdk/default.nix

@@ -7,13 +7,15 @@
 #   3) used by `google-cloud-sdk` only on GCE guests
 #
 
-{ stdenv, lib, fetchurl, makeWrapper, python, cffi, cryptography, pyopenssl,
-  crcmod, google-compute-engine, with-gce ? false }:
+{ stdenv, lib, fetchurl, makeWrapper, python, with-gce ? false }:
 
 let
-  pythonInputs = [ cffi cryptography pyopenssl crcmod ]
-                 ++ lib.optional (with-gce) google-compute-engine;
-  pythonEnv = python.withPackages (_: pythonInputs);
+  pythonEnv = python.withPackages (p: with p; [
+    cffi
+    cryptography
+    pyopenssl
+    crcmod
+  ] ++ lib.optional (with-gce) google-compute-engine);
 
   baseUrl = "https://dl.google.com/dl/cloudsdk/channels/rapid/downloads";
   sources = name: system: {