buildPythonPackage: do not keep checkInputs

When tests are disabled, we do not want to pass checkInputs to
stdenv.mkDerivation. This reduces the build requirements and, more
importantly, helps cutting cycles.

pkgs/development/interpreters/python/mk-python-derivation.nix

@@ -51,7 +51,7 @@ if disabled
 then throw "${name} not supported for interpreter ${python.executable}"
 else
 
-python.stdenv.mkDerivation (builtins.removeAttrs attrs ["disabled"] // {
+python.stdenv.mkDerivation (builtins.removeAttrs attrs ["disabled" "checkInputs"] // {
 
   name = namePrefix + name;