Remove GLFW_IM_MODULE session variable

Redundant thanks to https://github.com/nix-community/home-manager/pull/3331 being merged in home-manager

fcitx5.nix

@@ -21,10 +21,6 @@ in
     fcitx5.addons = with pkgs.fcitx-engines; [ anthy ];
   };
 
-  home.sessionVariables = {
-    GLFW_IM_MODULE = "ibus"; # IME support in kitty
-  };
-
   home.file = {
     "${themes}Nord-Dark".source = "${nord}/Nord-Dark";
     "${themes}Nord-Light".source = "${nord}/Nord-Light";