flake: remove NUR dependency

flake.lock

@@ -717,21 +717,6 @@
         "type": "indirect"
       }
     },
-    "nur": {
-      "locked": {
-        "lastModified": 1701461811,
-        "narHash": "sha256-5HP3qVDwyCSWCvW5B/HFBoqQNYFPYCgUklJd83aWRug=",
-        "owner": "nix-community",
-        "repo": "NUR",
-        "rev": "03f67bd929bf306ffeb389cabe00acc7d437cdd2",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-community",
-        "repo": "NUR",
-        "type": "github"
-      }
-    },
     "plymouth-themes": {
       "flake": false,
       "locked": {
@@ -780,7 +765,6 @@
         "nixos-conf-editor": "nixos-conf-editor",
         "nixpkgs": "nixpkgs_3",
         "nixpkgs-fixed-steam": "nixpkgs-fixed-steam",
-        "nur": "nur",
         "plymouth-themes": "plymouth-themes",
         "ranger-icons": "ranger-icons",
         "tlauncher": "tlauncher",