fix flake check

flake.lock

@@ -278,22 +278,6 @@
         "type": "github"
       }
     },
-    "nixpkgs_4": {
-      "locked": {
-        "lastModified": 1783522502,
-        "narHash": "sha256-iffAls3iaNTyJC2faYcUXSI+Gp02cDjYl+MygxKl2GI=",
-        "owner": "nixos",
-        "repo": "nixpkgs",
-        "rev": "0bb7ec54c8483066ec9d7720e780a5caa71f8612",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nixos",
-        "ref": "nixos-unstable",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
     "pyproject-build-systems": {
       "inputs": {
         "nixpkgs": [
@@ -578,7 +562,9 @@
     },
     "zineshop": {
       "inputs": {
-        "nixpkgs": "nixpkgs_4",
+        "nixpkgs": [
+          "nixpkgs"
+        ],
         "utils": "utils_4"
       },
       "locked": {