lib: remove listOrDagOf type

It has been deprecated for a long time and should be safe to remove.

tests/lib/types/default.nix

@@ -1,7 +1,6 @@
 {
   lib-types-dag-submodule = ./dag-submodule.nix;
   lib-types-dag-merge = ./dag-merge.nix;
-  lib-types-list-or-dag-merge = ./list-or-dag-merge.nix;
 
   lib-types-gvariant-merge = ./gvariant-merge.nix;
 }

tests/lib/types/list-or-dag-merge-result.txt

@@ -1,15 +0,0 @@
-before:before
-between:between
-after:after
-unnamed-1.1:k
-unnamed-1.2:l
-unnamed-2.01:a
-unnamed-2.02:b
-unnamed-2.03:c
-unnamed-2.04:d
-unnamed-2.05:e
-unnamed-2.06:f
-unnamed-2.07:g
-unnamed-2.08:h
-unnamed-2.09:i
-unnamed-2.10:j

tests/lib/types/list-or-dag-merge.nix

@@ -1,33 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-let
-  inherit (lib) concatStringsSep hm mkMerge mkOption types;
-
-  dag = lib.hm.dag;
-
-  result = let
-    sorted = dag.topoSort config.tested.dag;
-    data = map (e: "${e.name}:${e.data}") sorted.result;
-  in concatStringsSep "\n" data + "\n";
-
-in {
-  options.tested.dag = mkOption { type = hm.types.listOrDagOf types.str; };
-
-  config = {
-    tested = mkMerge [
-      { dag = [ "k" "l" ]; }
-      { dag = [ "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" ]; }
-      { dag.after = "after"; }
-      { dag.before = dag.entryBefore [ "after" ] "before"; }
-      { dag.between = dag.entryBetween [ "after" ] [ "before" ] "between"; }
-    ];
-
-    home.file."result.txt".text = result;
-
-    nmt.script = ''
-      assertFileContent \
-        home-files/result.txt \
-        ${./list-or-dag-merge-result.txt}
-    '';
-  };
-}