Change nixos github to nixos channel

flake.lock

···
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1749285348,
-        "narHash": "sha256-frdhQvPbmDYaScPFiCnfdh3B/Vh81Uuoo0w5TkWmmjU=",
-        "owner": "nixos",
-        "repo": "nixpkgs",
+        "lastModified": 1749393960,
+        "narHash": "sha256-qYyUe0adJrvE1imY6TDUgCao1WR2g6vIYzJ8SGcf3l0=",
         "rev": "3e3afe5174c561dee0df6f2c2b2236990146329f",
-        "type": "github"
+        "type": "tarball",
+        "url": "https://releases.nixos.org/nixos/unstable/nixos-25.11pre811950.3e3afe5174c5/nixexprs.tar.xz"
       },
       "original": {
-        "owner": "nixos",
-        "ref": "nixos-unstable",
-        "repo": "nixpkgs",
-        "type": "github"
+        "type": "tarball",
+        "url": "https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz"
       }
     },
     "nixpkgs_2": {

flake.nix

···
   description = "Shell with norgolith";
 
   inputs = {
-    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    nixpkgs.url = "https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz";
 
     norgolith.url = "github:NTBBloodbath/norgolith";
   };