flake.lock: Update

Flake lock file updates:

• Updated input 'nix':
    'github:DeterminateSystems/nix-src/5217e30' (2026-02-10)
  → 'https://api.flakehub.com/f/pinned/DeterminateSystems/nix-src/3.16.0/019c589d-45e9-7337-9ff0-a8d78fecf63f/source.tar.gz' (2026-02-13)

Author: cole-h

flake.lock

@@ -6,8 +6,7 @@
 
     crane.url = "https://flakehub.com/f/ipetkov/crane/*";
 
-    nix.url = "github:DeterminateSystems/nix-src";
-    # nix.url = "https://flakehub.com/f/NixOS/nix/=2.27.*";
+    nix.url = "https://flakehub.com/f/DeterminateSystems/nix-src/=3.16.*";
   };
 
   outputs =