Revert "lib: init flakes.nix"

This reverts commit PR #167947.

Flakes aren't standardised and the `lib` namespace shouldn't be
polluted with utilities that serve only experimental uses.

lib/default.nix

@@ -11,9 +11,6 @@ let
     callLibs = file: import file { lib = self; };
   in {
 
-    # interacting with flakes
-    flakes = callLibs ./flakes.nix;
-
     # often used, or depending on very little
     trivial = callLibs ./trivial.nix;
     fixedPoints = callLibs ./fixed-points.nix;
@@ -62,7 +59,6 @@ let
     # linux kernel configuration
     kernel = callLibs ./kernel.nix;
 
-    inherit (self.flakes) callLocklessFlake;
     inherit (builtins) add addErrorContext attrNames concatLists
       deepSeq elem elemAt filter genericClosure genList getAttr
       hasAttr head isAttrs isBool isInt isList isString length

lib/flakes.nix

@@ -1,22 +0,0 @@
-{ lib }:
-
-rec {
-
-  /* imports a flake.nix without acknowledging its lock file, useful for
-    referencing subflakes from a parent flake. The second argument allows
-    specifying the inputs of this flake.
-
-    Example:
-      callLocklessFlake {
-        path = ./directoryContainingFlake;
-        inputs = { inherit nixpkgs; };
-      }
-  */
-  callLocklessFlake = { path, inputs ? { } }:
-    let
-      self = { outPath = path; } //
-        ((import (path + "/flake.nix")).outputs (inputs // { self = self; }));
-    in
-    self;
-
-}

lib/tests/flakes/subflakeTest/flake.nix

@@ -1,8 +0,0 @@
-{
-  outputs = { self, subflake, callLocklessFlake }: rec {
-    x = (callLocklessFlake {
-      path = subflake;
-      inputs = {};
-    }).subflakeOutput;
-  };
-}

lib/tests/flakes/subflakeTest/subflake/flake.nix

@@ -1,5 +0,0 @@
-{
-  outputs = { self }: {
-    subflakeOutput = 1;
-  };
-}

lib/tests/misc.nix

@@ -22,16 +22,6 @@ in
 
 runTests {
 
-# FLAKES
-
-  testCallLocklessFlake = {
-    expr = callLocklessFlake {
-      path = ./flakes/subflakeTest;
-      inputs = { subflake = ./flakes/subflakeTest/subflake; inherit callLocklessFlake; };
-    };
-    expected = { x = 1; outPath = ./flakes/subflakeTest; };
-  };
-
 # TRIVIAL
 
   testId = {