stdenv: bootstrap darwin with python3

- Replaced python override from the final stdenv, instead we
  propagate our bootstrap python to stage4 and override both
  CF and xnu to use it.

- Removed CF argument from python interpreters, this is redundant
  since it's not overidden anymore.

- Inherit CF from stage4, making it the same as the stdenv.

pkgs/development/interpreters/python/default.nix

@@ -57,7 +57,7 @@ in {
       suffix = "";
     };
     sha256 = "0hds28cg226m8j8sr394nm9yc4gxhvlv109w0avsf2mxrlrz0hsd";
-    inherit (darwin) CF configd;
+    inherit (darwin) configd;
     inherit passthruFun;
   };
 
@@ -70,7 +70,7 @@ in {
       suffix = "";
     };
     sha256 = "0jdh9pvx6m6lfz2liwvvhn7vks7qrysqgwn517fkpxb77b33fjn2";
-    inherit (darwin) CF configd;
+    inherit (darwin) configd;
     inherit passthruFun;
   };
 
@@ -83,7 +83,7 @@ in {
       suffix = "";
     };
     sha256 = "1pj0mz1xl27khi250p29c0y99vxg662js8zp71aprkf8i8wkr0qa";
-    inherit (darwin) CF configd;
+    inherit (darwin) configd;
     inherit passthruFun;
   };
 
@@ -96,7 +96,7 @@ in {
       suffix = "";
     };
     sha256 = "0gskry19ylw91p38pdq36qcgk6h3x5i4ia0ik977kw2943kwr8jm";
-    inherit (darwin) CF configd;
+    inherit (darwin) configd;
     inherit passthruFun;
   };
 
@@ -109,7 +109,7 @@ in {
       suffix = "";
     };
     sha256 = "1s4lwn5vzsajlc88m6hkghsvnjw4d00l2dsgng0m2w6vyqbl32bm";
-    inherit (darwin) CF configd;
+    inherit (darwin) configd;
     inherit passthruFun;
   };
 
@@ -122,7 +122,7 @@ in {
       suffix = "a2";
     };
     sha256 = "02a301bdcldin05ksdg8xw8xr6gdkpf73p0cabvn9rdl6yhkr3q8";
-    inherit (darwin) CF configd;
+    inherit (darwin) configd;
     inherit passthruFun;
   };
 
@@ -136,6 +136,7 @@ in {
     ncurses = null;
     gdbm = null;
     sqlite = null;
+    configd = null;
     stripConfig = true;
     stripIdlelib = true;
     stripTests = true;