python3Packages.certifi: propgate cacert for its setup-hook

For tests that require a working ca-bundle via certifi we need to setup
`NIX_SSL_CERT_FILE`, which is kindly provided by cacerts setup-hook.

pkgs/development/python-modules/certifi/default.nix

@@ -30,16 +30,15 @@ buildPythonPackage rec {
     ln -snvf "${cacert}/etc/ssl/certs/ca-bundle.crt" "certifi/cacert.pem"
   '';
 
+  propagatedNativeBuildInputs = [
+    # propagate cacerts setup-hook to set up `NIX_SSL_CERT_FILE`
+    cacert
+  ];
+
   checkInputs = [
     pytestCheckHook
   ];
 
-  preCheck = ''
-    # NIX_SSL_CERT_FILE is set to /no-cert-file.crt during build, which
-    # breaks the tests
-    unset NIX_SSL_CERT_FILE
-  '';
-
   pythonImportsCheck = [
     "certifi"
   ];