hotfix: remove flake input

flake.lock

@@ -2,22 +2,35 @@
   "nodes": {
     "fenix": {
       "inputs": {
-        "nixpkgs": [
-          "nixpkgs-unstable"
-        ],
+        "nixpkgs": "nixpkgs",
         "rust-analyzer-src": "rust-analyzer-src"
       },
       "locked": {
-        "lastModified": 1711088506,
-        "narHash": "sha256-USdlY7Tx2oJWqFBpp10+03+h7eVhpkQ4s9t1ERjeIJE=",
+        "lastModified": 1711347842,
+        "narHash": "sha256-NEu85M2kpGlEBPVNSIB0nOSLWg3x6R3px5Nd+vthdsU=",
         "owner": "nix-community",
         "repo": "fenix",
-        "rev": "85f4139f3c092cf4afd9f9906d7ed218ef262c97",
+        "rev": "12619df460ea671b1e94a5c2c8c17ca91cb86ebe",
         "type": "github"
       },
       "original": {
-        "owner": "nix-community",
-        "repo": "fenix",
+        "id": "fenix",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1711163522,
+        "narHash": "sha256-YN/Ciidm+A0fmJPWlHBGvVkcarYWSC+s3NTPk/P+q3c=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "44d0940ea560dee511026a53f0e2e2cde489b4d4",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
         "type": "github"
       }
     },

flake.nix

@@ -5,7 +5,7 @@
     nixpkgs-unstable.url = "github:nixos/nixpkgs/nixos-unstable";
   };
 
-  outputs = { self, nixpkgs-unstable, utils, fenix, ... }:
+  outputs = { self, nixpkgs-unstable, utils, ... }:
     utils.lib.eachDefaultSystem
     (
       system: let