chore: drop unused custom packages

pkgs/fcitx5-themes.nix

@@ -1,38 +0,0 @@
-{
-  lib,
-  stdenv,
-  fetchFromGitHub,
-}:
-
-stdenv.mkDerivation {
-  pname = "fcitx5-themes";
-  version = "unstable-2022-09-28";
-
-  src = fetchFromGitHub {
-    owner = "thep0y";
-    repo = "fcitx5-themes";
-    rev = "9d6e437289aa8de61d2c198b2e6ce4b5edea204f";
-    hash = "sha256-iNOquWc6d1rgdWeGPBQ6na/bq+ZOV9cx4MCLf3SdBLg=";
-  };
-
-  phases = [
-    "unpackPhase"
-    "installPhase"
-  ];
-
-  installPhase = ''
-    runHook preInstall
-
-    rm -rf images README.md install.sh
-
-    mkdir -p $out/share/fcitx5/themes
-    cp -r * $out/share/fcitx5/themes
-    runHook postInstall
-  '';
-
-  meta = with lib; {
-    description = "fcitx5的简约风格皮肤——四季";
-    homepage = "https://github.com/thep0y/fcitx5";
-    platforms = platforms.all;
-  };
-}

pkgs/translate-shell.nix

@@ -1,37 +0,0 @@
-{
-  lib,
-  stdenvNoCC,
-  fetchFromGitHub,
-}:
-stdenvNoCC.mkDerivation rec {
-  pname = "translate-shell";
-  version = "0.9.7.1";
-
-  src = fetchFromGitHub {
-    owner = "soimort";
-    repo = pname;
-    rev = "gh-pages";
-    hash = "sha256-YQevXwslWzHen9n+Fn0a+oNx/EKg0Kd/Ge8ksYP0ekY=";
-  };
-
-  phases = [
-    "unpackPhase"
-    "installPhase"
-  ];
-
-  installPhase = ''
-    runHook preInstall
-
-    mkdir -p $out/bin
-    patchShebangs ./trans
-    cp ./trans $out/bin/trans
-
-    runHook postInstall
-  '';
-
-  meta = {
-    description = "Command-line translator using Google Translate, Bing Translator, Yandex.Translate, etc.";
-    homepage = "https://github.com/soimort/translate-shell";
-    license = lib.licenses.unlicense;
-  };
-}