feat: go back to nixpkgs nvim to reduce amount of IFD

flake/inputs.nix

@@ -59,11 +59,6 @@ let
   };
 
   nvimInputs = {
-    neovim-nightly = mkDep {
-      owner = "nix-community";
-      repo = "neovim-nightly-overlay";
-    };
-
     # uses nixVersions.nix_2_19
     nixd = mkDep {
       owner = "nix-community";
@@ -251,11 +246,6 @@ let
     }
 
     ## Theme sources
-    {
-      name = "jellyfin-ultrachromic-src";
-      owner = "CTalvio";
-      repo = "Ultrachromic";
-    }
     {
       name = "bat-theme-src";
       owner = "matt1432";

flake/lib.nix

@@ -12,12 +12,12 @@
     import input {
       inherit system;
       config.allowUnfree = true;
-      overlays = [
-        inputs.discord-overlay.overlays.default
-        inputs.grim-hyprland.overlays.default
-        inputs.jovian.overlays.default
-        inputs.nixpkgs-wayland.overlays.default
-        inputs.lix-module.overlays.default
+      overlays = map (i: inputs.${i}.overlays.default) [
+        "discord-overlay"
+        "grim-hyprland"
+        "jovian"
+        "lix-module"
+        "nixpkgs-wayland"
       ];
     };