Nixos: Move deprecated modules/derivation to separate folder

derivations/1_deprecated/firefox-gnome-theme/default.nix

@@ -0,0 +1,32 @@
+# Taken from https://github.com/tadfisher/flake/blob/main/pkgs/firefox-gnome-theme/default.nix
+# We don't use fetchTarbal or fetchFromGithub because we are using flakes:
+# - Specify the firefox-gnome-theme github repo as input in flake.nix
+# - We don't need to add sha256 or commit revision because it is automatically locked in flake.lock
+# - Pass the input to overlays/default.nix and from there to derivations/default.nix
+# - There we plug the input into the src argument of this derivation
+{
+  lib,
+  stdenv,
+  src,
+}:
+stdenv.mkDerivation {
+  pname = "firefox-gnome-theme";
+  version = "unstable";
+
+  inherit src;
+
+  dontConfigure = true;
+  dontBuild = true;
+  doCheck = false;
+
+  installPhase = ''
+    mkdir -p $out/share/firefox-gnome-theme
+    cp -r theme/* $out/share/firefox-gnome-theme
+  '';
+
+  meta = with lib; {
+    description = "A GNOME theme for Firefox";
+    homepage = "https://github.com/rafaelmardojai/firefox-gnome-theme";
+    license = licenses.unlicense;
+  };
+}