Nixos: Switch to standalone Home-Manager

Not everything is working yet, derivations have to be rewritten

overlays/default.nix

@@ -1,14 +1,13 @@
 {
   inputs,
   nixpkgs,
-  mylib,
   ...
 }: let
   # Taken from https://github.com/Misterio77/nix-config/blob/main/overlay/default.nix
   # By specifying this we can just add our derivation to derivations/default.nix and it will land here
   additions = final: prev:
     import ../derivations {
-      inherit inputs mylib;
+      inherit inputs;
       pkgs = final;
     };