libsForQt5.fcitx5-qt: add missing callPackage, fixes eval

https://github.com/NixOS/nixpkgs/pull/102168 moved Qt imports to qt5-packages.nix
and https://github.com/NixOS/nixpkgs/pull/104658 added a new package on the old
location.

pkgs/top-level/qt5-packages.nix

@@ -61,6 +61,8 @@ in (kdeFrameworks // plasma5 // plasma5.thirdParty // kdeApplications // qt5 //
 
   fcitx-qt5 = callPackage ../tools/inputmethods/fcitx/fcitx-qt5.nix { };
 
+  fcitx5-qt = callPackage ../tools/inputmethods/fcitx5/fcitx5-qt.nix { };
+
   qgpgme = callPackage ../development/libraries/gpgme { };
 
   grantlee = callPackage ../development/libraries/grantlee/5 { };