flake: add unstable

flake.lock

@@ -469,6 +469,21 @@
         "type": "indirect"
       }
     },
+    "nixpkgs-unstable": {
+      "locked": {
+        "lastModified": 1726937504,
+        "narHash": "sha256-bvGoiQBvponpZh8ClUcmJ6QnsNKw0EMrCQJARK3bI1c=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "9357f4f23713673f310988025d9dc261c20e70c6",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
     "plymouth-themes": {
       "flake": false,
       "locked": {
@@ -512,6 +527,7 @@
         "nix-index-database": "nix-index-database",
         "nixos-mailserver": "nixos-mailserver",
         "nixpkgs": "nixpkgs",
+        "nixpkgs-unstable": "nixpkgs-unstable",
         "plymouth-themes": "plymouth-themes",
         "ranger-icons": "ranger-icons",
         "tlauncher": "tlauncher",