nixos/tests: remove minimal-kernel module

It's not used, doesn't build, and seems like the only reason to have
`manualConfig` take `stdenv` as an argument.

nixos/lib/testing/legacy.nix

@@ -3,9 +3,10 @@ let
   inherit (lib) mkIf mkOption types;
 in
 {
-  # This needs options.warnings, which we don't have (yet?).
+  # This needs options.warnings and options.assertions, which we don't have (yet?).
   # imports = [
   #   (lib.mkRenamedOptionModule [ "machine" ] [ "nodes" "machine" ])
+  #   (lib.mkRemovedOptionModule [ "minimal" ] "The minimal kernel module was removed as it was broken and not used any more in nixpkgs.")
   # ];
 
   options = {

nixos/lib/testing/nodes.nix

@@ -23,7 +23,7 @@ let
               nixpkgs.config.allowAliases = false;
             })
           testModuleArgs.config.extraBaseModules
-        ] ++ optional config.minimal ../../modules/testing/minimal-kernel.nix;
+        ];
     };
 
 
@@ -78,14 +78,6 @@ in
       '';
     };
 
-    minimal = mkOption {
-      type = types.bool;
-      default = false;
-      description = mdDoc ''
-        Enable to configure all [{option}`nodes`](#test-opt-nodes) to run with a minimal kernel.
-      '';
-    };
-
     nodesCompat = mkOption {
       internal = true;
       description = mdDoc ''

nixos/modules/testing/minimal-kernel.nix

@@ -1,28 +0,0 @@
-{ config, pkgs, lib, ... }:
-
-let
-  configfile = builtins.storePath (builtins.toFile "config" (lib.concatStringsSep "\n"
-    (map (builtins.getAttr "configLine") config.system.requiredKernelConfig))
-  );
-
-  origKernel = pkgs.buildLinux {
-    inherit (pkgs.linux) src version stdenv;
-    inherit configfile;
-    allowImportFromDerivation = true;
-    kernelPatches = [ pkgs.kernelPatches.cifs_timeout_2_6_38 ];
-  };
-
-  kernel = origKernel // (derivation (origKernel.drvAttrs // {
-    configurePhase = ''
-      runHook preConfigure
-      mkdir ../build
-      make $makeFlags "''${makeFlagsArray[@]}" mrproper
-      make $makeFlags "''${makeFlagsArray[@]}" KCONFIG_ALLCONFIG=${configfile} allnoconfig
-      runHook postConfigure
-    '';
-  }));
-
-   kernelPackages = pkgs.linuxPackagesFor kernel;
-in {
-  boot.kernelPackages = kernelPackages;
-}