nixos/unity3d: remove since the corresponding package was removed too

This should have had happened in 2022 when pkgs.unity3d was removed from
nixpkgs in 4161b3d11f.

nixos/modules/rename.nix

@@ -109,6 +109,11 @@ in
       consider using `programs.pay-respects` instead.
     '')
     (mkRemovedOptionModule [ "programs" "tilp2" ] "The corresponding package was removed from nixpkgs.")
+    (mkRemovedOptionModule [
+      "programs"
+      "unity3d"
+      "enable"
+    ] "The corresponding package was removed from nixpkgs in 2022.")
     (mkRemovedOptionModule [ "programs" "way-cooler" ] (
       "way-cooler is abandoned by its author: "
       + "https://way-cooler.org/blog/2020/01/09/way-cooler-post-mortem.html"

nixos/modules/security/chromium-suid-sandbox.nix

@@ -9,13 +9,6 @@ let
   sandbox = pkgs.chromium.sandbox;
 in
 {
-  imports = [
-    (lib.mkRenamedOptionModule
-      [ "programs" "unity3d" "enable" ]
-      [ "security" "chromiumSuidSandbox" "enable" ]
-    )
-  ];
-
   options.security.chromiumSuidSandbox.enable = lib.mkOption {
     type = lib.types.bool;
     default = false;