fix(flake): use nixvim's nixpkgs instead of our own

This ensures the `nixpkgs-unstable` we consume is tested against
`nixvim`.

flake-modules/nvim.nix

@@ -1,7 +1,5 @@
 { inputs, ... }:
 {
-  flake.overlays.nixvim = inputs.nixvim.overlays.default;
-
   perSystem =
     { lib, system, ... }:
     let

flake.lock

@@ -295,6 +295,22 @@
         "type": "github"
       }
     },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1738797219,
+        "narHash": "sha256-KRwX9Z1XavpgeSDVM/THdFd6uH8rNm/6R+7kIbGa+2s=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "1da52dd49a127ad74486b135898da2cef8c62665",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "nixvim": {
       "inputs": {
         "devshell": [],
@@ -307,20 +323,18 @@
           "home-manager"
         ],
         "nix-darwin": [],
-        "nixpkgs": [
+        "nixpkgs": "nixpkgs_2",
-          "unstable"
-        ],
         "nuschtosSearch": [],
         "treefmt-nix": [
           "treefmt-nix"
         ]
       },
       "locked": {
-        "lastModified": 1738622717,
+        "lastModified": 1738966895,
-        "narHash": "sha256-XSFbbhN8xdr4qKRFbubXJ3vkSusKSnALf69G9fdGPXE=",
+        "narHash": "sha256-OXOh35rTEnFSO4vj/SDMIlDvFPGW0ba1XhZkfx+AlL0=",
         "owner": "nix-community",
         "repo": "nixvim",
-        "rev": "6288354d43ada972480cbd10dc7102637eeafc1e",
+        "rev": "e7f20a602f6e08a70045f36c531bc44ba1baed07",
         "type": "github"
       },
       "original": {
@@ -339,7 +353,10 @@
         "stylix": "stylix",
         "systems": "systems",
         "treefmt-nix": "treefmt-nix",
-        "unstable": "unstable"
+        "unstable": [
+          "nixvim",
+          "nixpkgs"
+        ]
       }
     },
     "stylix": {
@@ -468,22 +485,6 @@
         "repo": "treefmt-nix",
         "type": "github"
       }
-    },
-    "unstable": {
-      "locked": {
-        "lastModified": 1738410390,
-        "narHash": "sha256-xvTo0Aw0+veek7hvEVLzErmJyQkEcRk6PSR4zsRQFEc=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "3a228057f5b619feb3186e986dbe76278d707b6e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-unstable",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
     }
   },
   "root": "root",

flake.nix

@@ -3,10 +3,13 @@
   # A helpful description of your flake
   description = "My NixOS configuration";
 
+  # Trick renovate into accepting this lockfile (see https://github.com/renovatebot/renovate/issues/29721)
+  # "github:NixOS/nixpkgs/nixos-unstable"
+
   # Flake inputs
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
-    unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
+    unstable.follows = "nixvim/nixpkgs";
     # Lix
     lix-module = {
       url = "https://git.lix.systems/lix-project/nixos-module/archive/2.92.0.tar.gz";
@@ -35,7 +38,6 @@
     nixvim = {
       url = "github:nix-community/nixvim";
       inputs = {
-        nixpkgs.follows = "unstable";
         home-manager.follows = "home-manager";
         flake-parts.follows = "flake-parts";
         treefmt-nix.follows = "treefmt-nix";