python3: Whitelist config options when overriding interpreter

In the case of cross compilation we don't want pass through build
inputs from the cross platform, but we do want to pass on config options.

pkgs/development/interpreters/python/cpython/default.nix

@@ -85,7 +85,8 @@ let
 
   passthru = let
     # When we override the interpreter we also need to override the spliced versions of the interpreter
-    override = attr: let python = attr.override (inputs // { self = python; }); in python;
+    inputs' = lib.filterAttrs (_: v: ! lib.isDerivation v) inputs;
+    override = attr: let python = attr.override (inputs' // { self = python; }); in python;
   in passthruFun rec {
     inherit self sourceVersion packageOverrides;
     implementation = "cpython";