treewide: remove redundant rec

pkgs/tools/inputmethods/fcitx-engines/fcitx-skk/default.nix

@@ -1,6 +1,6 @@
 { stdenv, fetchFromGitHub, cmake, pkgconfig, fcitx, libskk, skk-dicts }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
   pname = "fcitx-skk";
   version = "0.1.4";
   src = fetchFromGitHub {

pkgs/tools/inputmethods/ibus-engines/ibus-table-chinese/default.nix

@@ -13,7 +13,7 @@ let
     rev = "7d5297759aef4cd086bdfa30cf6d4b2ad9446992";
     sha256 = "0mx9jvxpiva9v2ffaqlyny48iqr073h84yw8ln43z2avv11ipr7n";
   };
-in stdenv.mkDerivation rec {
+in stdenv.mkDerivation {
   pname = "ibus-table-chinese";
   version = "1.8.2";
 

pkgs/tools/inputmethods/ibus/default.nix

@@ -60,7 +60,7 @@ let
       sha256 = "a1a3ca4381eb91f7b65afe7cb7df615cdcf67993fef4b486585f66b349993a10";
     };
   };
-  ucd = stdenv.mkDerivation rec {
+  ucd = stdenv.mkDerivation {
     name = "ucd-12.0.0";
     dontUnpack = true;
     installPhase = ''

pkgs/tools/inputmethods/keyfuzz/default.nix

@@ -1,6 +1,6 @@
 { stdenv, fetchurl }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
   pname = "keyfuzz";
   version = "0.2";
 

pkgs/tools/inputmethods/skk/skk-dicts/default.nix

@@ -27,7 +27,7 @@ let
   };
 in
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
   pname = "skk-dicts-unstable";
   version = "2017-10-26";
   srcs = [ small medium large edict assoc ];

pkgs/tools/inputmethods/skk/skktools/default.nix

@@ -8,7 +8,7 @@
 #   dependencies on a Ruby interpreter etc.
 # - We for the moment do not package them to keep the dependencies slim.
 #   Probably, shall package the newer tools as skktools-extra in the future.
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
   pname = "skktools";
   version = "1.3.3";
   src = fetchFromGitHub {

pkgs/tools/inputmethods/tegaki-zinnia-japanese/default.nix

@@ -1,6 +1,6 @@
 { stdenv, fetchurl, unzip }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
   pname = "tegaki-zinnia-japanese";
   version = "0.3";
 

pkgs/tools/inputmethods/zinnia/default.nix

@@ -1,6 +1,6 @@
 { stdenv, fetchFromGitHub }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation {
   pname = "zinnia";
   version = "2016-08-28";