Revert "nixos/version: fix nixops pre 1.6 compatibility"

This reverts commit 70c6f6572d.

nixos/modules/misc/version.nix

@@ -16,21 +16,6 @@ in
 
   options.system = {
 
-    # XXX: Reintroduce old options to make nixops before 1.6 able to evaluate configurations
-    # XXX: Remove after nixops has been bumped to a compatible version
-    nixosVersion = mkOption {
-      readOnly = true;
-      internal = true;
-      type = types.str;
-      default = config.system.nixos.version;
-    };
-    nixosVersionSuffix = mkOption {
-      readOnly = true;
-      internal = true;
-      type = types.str;
-      default = config.system.nixos.versionSuffix;
-    };
-
     nixos.version = mkOption {
       internal = true;
       type = types.str;

nixos/modules/rename.nix

@@ -197,9 +197,9 @@ with lib;
     (mkRenamedOptionModule [ "virtualization" "growPartition" ] [ "boot" "growPartition" ])
 
     # misc/version.nix
-    #(mkRenamedOptionModule [ "config" "system" "nixosVersion" ] [ "config" "system" "nixos" "version" ])
+    (mkRenamedOptionModule [ "config" "system" "nixosVersion" ] [ "config" "system" "nixos" "version" ])
     (mkRenamedOptionModule [ "config" "system" "nixosRelease" ] [ "config" "system" "nixos" "release" ])
-    #(mkRenamedOptionModule [ "config" "system" "nixosVersionSuffix" ] [ "config" "system" "nixos" "versionSuffix" ])
+    (mkRenamedOptionModule [ "config" "system" "nixosVersionSuffix" ] [ "config" "system" "nixos" "versionSuffix" ])
     (mkRenamedOptionModule [ "config" "system" "nixosRevision" ] [ "config" "system" "nixos" "revision" ])
     (mkRenamedOptionModule [ "config" "system" "nixosCodeName" ] [ "config" "system" "nixos" "codeName" ])
     (mkRenamedOptionModule [ "config" "system" "nixosLabel" ] [ "config" "system" "nixos" "label" ])