migrated tasks and downloads to this flake

pkgs/download.nix

@@ -0,0 +1,37 @@
+{
+  python3Packages,
+  gallery-dl,
+  ffmpeg,
+  callPackage,
+  ...
+}:
+let
+  pname = "download";
+  version = "2.5";
+in
+python3Packages.buildPythonApplication {
+  inherit pname version;
+
+  src = builtins.path {
+    path = ../src/download/.;
+    name = "${pname}-${version}";
+  };
+
+  pyproject = true;
+
+  build-system = [ python3Packages.setuptools ];
+
+  dependencies =
+    [
+      ffmpeg
+      gallery-dl
+      (callPackage ./webcomix.nix { })
+    ]
+    ++ builtins.attrValues {
+      inherit (python3Packages)
+        pyyaml
+        types-pyyaml
+        yt-dlp
+        ;
+    };
+}