flake.lock: Update

Flake lock file updates:

```
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/78add7b7abb61689e34fc23070a8f55e1d26185b' (2025-05-28)
  → 'github:nixos/nixpkgs/1f426f65ac4e6bf808923eb6f8b8c2bfba3d18c5' (2025-06-23)
• Updated input 'nixpkgs-unstable':
    'github:nixos/nixpkgs/910796cabe436259a29a72e8d3f5e180fc6dfacc' (2025-05-31)
  → 'github:nixos/nixpkgs/4b1164c3215f018c4442463a27689d973cffd750' (2025-06-24)
• Updated input 'treefmt-nix':
    'github:numtide/treefmt-nix/1f3f7b784643d488ba4bf315638b2b0a4c5fb007' (2025-05-26)
  → 'github:numtide/treefmt-nix/a05be418a1af1198ca0f63facb13c985db4cb3c5' (2025-06-06)
```

flake.lock

@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1750330365,
+        "lastModified": 1750646418,
-        "narHash": "sha256-hJ7XMNVsTnnbV2NPmStCC07gvv5l2x7+Skb7hyUzazg=",
+        "narHash": "sha256-4UAN+W0Lp4xnUiHYXUXAPX18t+bn6c4Btry2RqM9JHY=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "d883b6213afa179b58ba8bace834f1419707d0ad",
+        "rev": "1f426f65ac4e6bf808923eb6f8b8c2bfba3d18c5",
         "type": "github"
       },
       "original": {
@@ -36,11 +36,11 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1750365781,
+        "lastModified": 1750741721,
-        "narHash": "sha256-XE/lFNhz5lsriMm/yjXkvSZz5DfvKJLUjsS6pP8EC50=",
+        "narHash": "sha256-Z0djmTa1YmnGMfE9jEe05oO4zggjDmxOGKwt844bUhE=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "08f22084e6085d19bcfb4be30d1ca76ecb96fe54",
+        "rev": "4b1164c3215f018c4442463a27689d973cffd750",
         "type": "github"
       },
       "original": {